Rationalism—Socrates-Plato, Descartes, Spinoza, the Enlightenment (Part 3)
Descartes, Spinoza, & the Enlightenment
Rene Descartes (1596-1650)
Rene Descartes was a French Catholic who contributed to the theory of continental rationalism (i.e., rationalism on the main European continent). Descartes sought the type of rational certainty that he perceived in mathematics. Descartes emphasized the reality of universals or objective universal principles about the nature of reality, that the final test of truth was the principle of logical non-contradiction, derogated perception/sense experience (empiricism) because the senses could be misled, and assumed that whatever is real is rational.
Reality of universals
Final test of truth is the principle of contradiction
Derogated perception/sense experience
Whatever is real is rational (unproven by reason/presupposed)
How can these things be known or proven without first assuming them to be true?
The starting point for this version of rationalism can be summarized as methodological doubt.
This method sought to doubt everything but that which cannot be doubted then work from that first fundamental principle to other reality.
The famous statement of Descartes which was his contribution to rationalistic philosophy was cogito ergo sum (in Latin) or “I think, therefore I am/exist.”15
The concept behind this statement is that even if one doubts his own existence, he must exist in order to doubt it. Some have even rephrased the statement as dubito ergo sum (“I doubt, therefore I am/exist”).
Even if I doubt my own existence, who is doubting? I am. I doubt or think, therefore, I exist. In a fuller version of the famous quote, Descartes explains further,
“As long as we are doubting, we cannot doubt that we exist; and this is the first thing we know when philosophizing methodically. Thus by rejecting all those things that we can in any way doubt and even pretending that they are false, we easily suppose that there is no God, that there are no heavens or bodies, and that we ourselves have no hands or feet, nor indeed any body at all – but not, however, in such a way that we, who think these thoughts, are nothing. For it is impossible for us to think that whatever thinks does not exist during the very time that it thinks. Therefore [despite the most extravagant assumptions, we cannot prevent ourselves from believing that this inference] this knowledge, ‘I am thinking, therefore I exist’, is the foremost and most certain that occurs to anyone who philosophizes methodically.”16
From this self-referential starting point, Descartes argued that he could thus reason to the knowledge of God then to the knowledge of the rest of creation. Descartes also concluded that the nature of reality was dualistic—mind and body, non-physical reality and physical reality—but he could not consistently explain how they impacted one another.
Descartes model: Self—God—Creation
Dualism—mind and body
“What is the mind? No matter. What is matter? Never mind.”
Philosophically, knowledge has been defined as justified true belief. Even if a belief is true it is not allowed to be arbitrary. In other words, one must believe the truth for the right reason(s). Therefore, even if we agree with the conclusion(s), we may still be required to challenge the premises or reasoning that led to the correct conclusion if it is faulty.
How can these things be known or proven without first assuming them to be true?
Is self an appropriate and valid starting point for evaluating reality?
Circular reasoning/Question-begging (Proverbs 26:4-5)
“I think, therefore I am/I exist.”
Is this valid logical reasoning?
Premise: “I think...”
Conclusion: “...I exist.”
“I think, therefore I am.”
Existence is already assumed before thinking (“I think”). Self and existence must therefore be assumed even before thinking according to this argument. This type of rationalism must assume what it seeks to prove, therefore, it is arbitrary. In addition, it is also incomplete because other items exist without thinking (rocks, trees, etc.).
Augustine
The argumentation of Descartes can be used appropriately, apologetically, and even Biblically but it cannot establish a valid ultimate authority. This argument can be used to attack epistemological skepticism or denial of absolute truth but is not sufficient to establish truth about the nature of reality. In fact, this argument is not new and may even have been plagiarized from Augustine.
In response to Academic skepticism that questioned the possibility of any knowledge of objective truth whatsoever, even knowledge of our own existence, Augustine wrote,
“For we both are, and know that we are, and delight in our being, and our knowledge of it.... But, without any delusive representation of images or phantasms, I am most certain that I am, and that I know and delight in this. In respect of these truths, I am not at all afraid of the arguments of the Academicians, who say, What if you are deceived? For if I am deceived, I am. For he who is not, cannot be deceived; and if I am deceived, by this same token I am. And since I am if I am deceived, how am I deceived in believing that I am? for it is certain that I am if I am deceived. Since, therefore, I, the person deceived, should be, even if I were deceived, certainly I am not deceived in this knowledge that I am. And, consequently, neither am I deceived in knowing that I know. For, as I know that I am, so I know this also, that I know.”17 (emphasis added)
The main Biblical problem with this type of rationalistic argument, as seen in Descartes, is that it assumes self as the ultimate starting point for reasoning and knowledge rather than the proximate starting point. Biblically, we exist within God’s world and we know God as we know ourselves and know ourselves as we know God.
Acts 17:28—“for in Him we live and move and exist [Lit are],…”
Romans 1:19—“because that which is known about God is evident within them; for God made it evident to them.”
John Calvin
“Our wisdom, in so far as it ought to be deemed true and solid Wisdom, consists almost entirely of two parts: the knowledge of God and of ourselves. But as these are connected together by many ties, it is not easy to determine which of the two precedes and gives birth to the other. For, in the first place, no man can survey himself without forthwith turning his thoughts towards the God in whom he lives and moves [Acts 17:28]; because it is perfectly obvious, that the endowments which we possess cannot possibly be from ourselves; nay, that our very being is nothing else than subsistence in God alone.”18
Existence and a mind that can recognize and think meaningfully about that existence is a result of the internal revelation of the knowledge of the Creator-God of the Bible.
Necessary Being vs. Contingent Being
We, as human beings, do not have necessary being. There was existence before us and there will be existence after us. Other reality does not exist because we exist to experience it or think about it. God, on the other hand, has necessary being. On His being depends the being and existence of all else, yet His being is dependent on nothing and no one outside Himself (cf. Romans 11:36).
Exodus 3:14—“God said to Moses, ‘I AM WHO I AM’; and He said, ‘Thus you shall say to the sons of Israel, “I AM has sent me to you.”’”
Isaiah 43:10—“‘You are My witnesses,’ declares the Lord,
‘And My servant whom I have chosen,
So that you may know and believe Me
And understand that I am He.
Before Me there was no God formed,
And there will be none after Me.”
John 8:58—“Jesus said to them, ‘Truly, truly, I say to you, before Abraham was born [Lit came into being], I am.’”
John 1:3—“All things came into being through Him, and apart from Him nothing came into being that has come into being.” (cf. Colossians 1:16)
Both existence and thinking can only meaningfully exist if reality is as the Bible describes it. Otherwise, existence and thinking simply exists in a changing chance-universe in which nothing can be known about the nature of reality or the mind that knows it.
“The theistic proofs therefore reduce to one proof, the proof which argues that unless this God, the God of the Bible, the ultimate being, the Creator, the controller of the universe, be presupposed as the foundation of human experience, this experience operates in a void. This one proof is absolutely convincing.”19
The possible Biblical alternative to the self-referential rationalism of Descartes that says, “I think, therefore I am,” rather begins with the existence and attributes of God as the basis for our own existence and thinking—“I think, therefore, I AM (Exodus 3:14)” or “I AM, therefore, you think (Exodus 3:14).”
Baruch Spinoza (1632-1677)
Spinoza was a Dutch Jewish philosopher responsible for developing the theory of rationalistic pantheism. Unlike the dualism of Plato and Descartes, Spinoza claimed to use reason (with a different definition), Spinoza argued for monism—the theory that all reality is fundamentally one.
Ontological monism—there is only one substance, known as God or nature, with two attributes, corresponding to mind and body.20
This rationalistic view of reality did not lead to an outright rejection of God but a pantheistic view of God and Nature as the fundamental reality. In other words, “God” or “Nature” was just the name for the totality of reality, not the transcendent Creator described by the Bible.
“Whatever is, is in God, and nothing can exist or be conceived without God.”21
If “God” is all nature and all nature is “God,” then nothing can be meaningfully said about “God” in particular. This philosophy is an attempt to affirm the existence of “God” in name but is actually a denial of God through redefinition. This influenced Christianity because it allowed atheists and other non-believers to continue to declare themselves to be “Christians” because they utilize common terminology but redefine it.
“Spinoza’s denial, on the basis of strict philosophical reasoning, of the existence of a transcendent supreme being, his identification of God with nature, gives strong impetus to the strands of atheism and naturalism that thread through Enlightenment philosophy.”22
In the final analysis, all Spinoza has given us is a set of definitions. According to this worldview, one would have to know everything (omniscience) in order to know anything. We would have to have a full awareness of all reality to have a rational view of any particular area of reality. In this theory, knowledge becomes impossible without omniscience.
Spinoza demonstrated that reason could be used as a tool but could not establish ultimate authority.
The Enlightenment (ca. 1650-1800)
The American Revolution took place (and was influenced by) the period later known as the Enlightenment. The focus of the Enlightenment was the use of reason to question authority, hence the revolutionary character of the time. This period is known for the English, American, and French revolutions. The use of self-evident reason to question authority led to a questioning of political authority (e.g., Thomas Jefferson’s Declaration of Independence [1776]).
“Enlightenment is the process of undertaking to think for oneself, to employ and rely on one’s own intellectual capacities in determining what to believe and how to act.”23
While there is great value in thinking for ourselves apart from arbitrary authority, are our minds and autonomous human reason sufficient to establish the knowledge of universal truth?
“…for all the enduring accomplishments of Enlightenment political philosophy, it is not clear that human reason proves powerful enough to put a concrete, positive authoritative ideal in place of the ideals negated by rational criticism. As in the epistemological domain, reason shows its power more convincingly in criticizing authorities than in establishing them.”24
Conclusion(s)
Reason is a God-given tool to be used in submission to and dependence on God and His revelation (cf. Isaiah 1:18) but reason cannot operate as an autonomous, independent source of authority.
Rationalism claims to be able to establish certainty by the use of reasoning from self-evident truths, however, so-called rationalistic systems of thought contradict one another, undermine themselves, and lead to arbitrary conclusions rather than to certainty.
Rationalism is self-defeating because it must assume the validity of reason in order to prove the validity of reason.
Rationalism also claims to utilize reason, but led philosophers to radically diverse conclusions, even irrational speculations.
“We must point out...that univocal [having only one possible meaning] reasoning itself leads to self-contradiction, not only from a theistic point of view, but from a non-theistic point of view as well... It is this that we ought to mean when we say that we reason from the impossibility of the contrary. The contrary is impossible only if it is self-contradictory when operating on the basis of its own assumptions.”25
2 Corinthians 10:5—“We are destroying speculations and every lofty thing raised up against the knowledge of God, and we are taking every thought captive to the obedience of Christ,”
Rationalism contributed a useful critique of empiricism and skepticism, encouraged the use of reason, and championed universal absolute truth, however, what was useful as a tool was insufficient as an authority. Rationalism contributed a useful mindset about the limits of sense perception (empiricism) and defended absolute truth but was unable to establish authoritative certainty.
Psalm 94:11—“The Lord knows the thoughts of man,
That they are a mere breath.” (cf. 1 Corinthians 3:20)
Proverbs 28:26—“He who trusts in his own heart [mind] is a fool [cf. Proverbs 1:7],
But he who walks wisely will be delivered.”
Biblical reasoning ought to be an act of obedience, to think in accordance with God’s revealed nature, character, and will, not autonomous human thought.
Reasoning demonstrates that men know God (cf. Romans 1:19), we must demonstrate to the unbelieving rationalist the insufficiency of autonomous human reason as an ultimate authority and the inability to use reason consistently without the acknowledgement of the Creator-God of Scripture. Evangelistically, we repeat the statement of God, “Come, let us reason together” (Isaiah 1:18), to call the unbelieve to repentance and salvation.
Footnotes/Further Resources:
[15] Rene Descartes, Discourse on Method and Meditations on First Philosophy, trans. Donald A Cress, (Indianapolis, IN.: Hackett Publishing Company, 1998, fourth edition) p. 18, Online version
[16] Rene Descartes, Meditations and Other Metaphysical Writings, (Penguin Classics), pp. 113-114
[17] Augustine, City of God, 11.26, in Nicene and Post-Nicene Fathers Series I, Volume 2 (NPNF1-02) (ed. Philip Schaff), (Christian Classics Ethereal Library), p. 503, Online version
[18] John Calvin, Institutes of the Christian Religion, 1.1.1, Online version
[19] Van Til, Common Grace and the Gospel, Online version, p. 126
[20] Bristow, William, "Enlightenment", The Stanford Encyclopedia of Philosophy (Fall 2017 Edition), Edward N. Zalta (ed.), URL = <https://plato.stanford.edu/archives/fall2017/entries/enlightenment/>
[21] Spinoza, as quoted in Roger Scruton, Spinoza: A Very Short Introduction (Oxford University Press, 2002), p. 38
[22] Bristow, William, "Enlightenment", The Stanford Encyclopedia of Philosophy (Fall 2017 Edition), Edward N. Zalta (ed.), URL = <https://plato.stanford.edu/archives/fall2017/entries/enlightenment/>
[23] Stanford Encyclopedia of Philosophy, “Enlightenment,” first published Friday, August 20, 2010, Online version
[24] Ibid.
[25] Cornelius Van Til, A Survey of Christian Epistemology (Philadelphia, P.A.: Presbyterian and Reformed, 1969), p. 204, Online version
Applied Apologetics - Biblical/Christian Philosophy (YouTube Playlist)
Rationalism - Socrates-Plato, Descartes, Spinoza, the Enlightenment (Part 1) (YouTube)
Rationalism - Socrates-Plato, Descartes, Spinoza, the Enlightenment (Part 2) (YouTube)
Rationalism - Socrates-Plato, Descartes, Spinoza, the Enlightenment (Part 3) (YouTube)