Friday, December 31, 2010

Aquinas, Descartes, and Schaeffer

This post consists of the fruit of some investigations related to a combox discussion on this post. My interlocutor suggests that Schaeffer is correct in proposing that Aquinas paved the way for Descartes. I deny this for the reasons already presented in that post and in the subsequent comments. Here are a few more hopefully helpful bits on the subject. As an aside, I think it’s worth noting that it is Descartes who is regarded as the father of modern philosophy and not Aquinas.

John Peterson writes in Aquinas: A New Introduction, with respect to metaphysics:

[T]he temptation is to conclude that Aquinas was a Cartesian before Descartes. For both philosophers avoid the extremes of materialism on the one hand and idealism on the other. They both deny either that all is matter or that all is mind.

Yet there are important differences between the two philosophers. That is partly due to the fact that Aquinas was less of a Platonist than was Descartes on the matter of persons. For Descartes, a person’s soul or mind is a complete substance, just as it is for Plato. But for Aquinas, who is here closer to Aristotle, a person’s soul is not a complete substance in its own right but rather the form of his or her body. For wider philosophical reasons, Descartes rejected outright the analysis of natural things into form and matter. For that reason, he could not and would not have applied the form-matter schema to the analysis of persons. So even though they are together in denying what is now called identity materialism (as well as, for that matter, epiphenomenalism), the two philosophers part company as regards the sort of thing the spiritual human soul is, i.e. whether it is a complete substance or the (incomplete) form of a substance. [p. xi, available here; emphasis added]

In my view this is a fundamental difference for the present discussion. On the one hand it is consistent both with Descartes’ rationalism (which Aquinas did not share) and with his famous insistence upon starting his philosophical inquiry with himself (or, to be more precise, with his own rational powers)—which Aquinas also did not share.

In a related vein we find the following in The Cambridge Companion to Aquinas. Joseph Owens writes there:

Common to both Aristotle and Aquinas is the tenet that all naturally attainable knowledge originates in external sensible things. By their efficient causality transmitted through the appropriate media, the external things impress their forms upon the human cognitive faculties, and thereby make the percipient be the thing perceived in the actuality of the cognition. The awareness is directly of the thing itself, and only concomitantly and reflexively of the percipient and of the cognitive acts. The external things remain epistemologically prior. From this viewpoint both Aristotle and Aquinas remain radically distinct from modern philosophers, who from Descartes on base their philosophy upon ideas or sensations or vivid phenomena, instead of immediately on external things themselves. Likewise, both Aristotle and Aquinas remain just as distinct from postmodern thinkers who look for their starting points in linguistic and historical formation. [53; emphasis added]

So we see here that Owens too traces the beginnings of modern philosophy not to Aquinas (pace my interlocutor) but to Descartes, and identifies a “radical distinction” between the two.

In the Routledge Encyclopedia of Philosophy article on Descartes, we read the following:

Descartes rejected the Aristotelian philosophy as soon as he left school. … [I]t is probable that what dissatisfied him most in what he had been taught was natural philosophy. [Page 4, which may be seen here]

If Descartes rejected the philosophy, how can it reasonably be said that he was dependent upon Aquinas?

Elsewhere we read:

Descartes did not publish anything until he was forty years old, largely due to his fears of censure.

Why would he fear censure if his views were consistent with those of Aquinas? Answer: he wouldn’t. But he did, because they weren’t.

And again:

Descartes self-consciously rejected the philosophical heritage of scholasticism, and attempted to formulate a new philosophical method and construct of new system of philosophical knowledge. It should be noted that Descartes did concede to theology the role that it occupied in the mediaeval period and still occupied in the church of his day; yet justifiably historians attribute this concession to his fear of persecution of ecclesiastical authorities. His statement, “That we must believe all that God has revealed, even though it is above the range of our capacities” (Principles 1.25) is anomalous in his system based on systematic doubt. [Emphasis added]

I think it’s pretty clear that we may safely deny any substantive Thomistic influence on Descartes. Schaeffer was wrong.


daniel4wr said...


If Descartes is the father of modern philosophy, that would make Aquinas its grandfather!

I see now that you were only feigning ignorance when you asked me if there was anyone under the sun who agreed with Francis Schaeffer. Your Peterson and Owens quotes above show that many must think that “Aquinas was a Cartesian before Descartes” otherwise these men would not take such pains to dispel the notion.

Let’s review for the new readers what we’ve established in our discussion on your earlier post. First, we have established Aquinas’ Affirmation that (in your words) “reason can arrive at truth, and that is not dependent upon theology to do so." Second, we have established that Modern Rationalism (expressed in Descartes’ axiom “I think, therefore I am”) is founded upon the principle that man beginning only with his reason can arrive at truth without resort to God's revelation in Scripture. So, we can conclude that Aquinas affirms the foundation on which Modern Rationalism was built. Neither Peterson nor Owens respond to this conclusion in the quotations you provide.

Peterson notes that Aquinas had an Aristotelian view of the human soul while Descartes’ view was more Platonic. Irrelevant! What is relevant is that Aquinas and Descartes both build on the same foundation that man using reason alone can arrive at truth without resort to the revelation of Scripture. What they end up building on that foundation is different: Aquinas concludes with his human reason that man’s soul is a complete substance, whereas Descartes concludes that it is the form of a substance. But it doesn’t matter what they ended up concluding. What matters is that their conclusions are based on the same foundation.

Owens notes that Aquinas and Descartes had different views as to the source of the raw material which human reason could use to build its conclusions. Aquinas used only “external sensible things” while Descartes also included ideas and sensations and vivid phenomena. Irrelevant! Again, the two men began on the same foundation that human reason can arrive at truth independent of Scripture. It does not matter that in their search for that truth one considered only external things while the other considered ideas and sensations.

Similarly, Descartes’ rejection of Aristotelian philosophy and his fear of censure just show that Descartes, using human reason independent of Scripture, came to different conclusions than Aquinas. But there can be no doubting or disputing that Aquinas affirmed the underlying principle upon which Descartes based his philosophy, namely, that man using reason alone can arrive at truth independent of Scripture. Francis Schaeffer was right.

Dan Lawler a/k/a The Interlocutor

Scott said...

I found the exchange between you two on the previous post interesting (having read and loved Schaeffer's foundational works and having begun to appreciate Aquinas). I can see merit in both perspectives. Despite thoroughly enjoying Schaeffer, it seems that he tries to extend his reach too far sometimes and fit history into his paradigm rather than the other way around. Nevertheless, I didn't get the impression that Schaeffer's criticism (which was mixed, I should say, with praise for Aquinas for bringing things down to earth, so to speak) went beyond the suggestion that Aquinas's emphasis helped lead to the rationalism that is wholly separated from revelation--no matter the sincerity or truth of his arguments. And this seems plausible to me.

By the way, I have an unrelated question for you Reginald. I'm writing an undergraduate thesis on the nature of the self in Flannery O'Connor's short story "Revelation." I am going to be contrasting her Catholic view from the views of psychoanalytic critics (Freud, Lacan, Levinas, etc.), and would like to do so from a Thomist standpoint (since her theology was heavily indebted to him). Can you point me to where Aquinas addresses this issue (i.e. self-identity in relation to Christ)? Being a Reformed Protestant, I'm a bit in the dark when it comes to Aquinas (though I'm increasingly learning that I shouldn't be), and would appreciate any help you could offer. Feel free to e-mail ( a response to this if you want to leave your comment area uncluttered. Thanks!


Reginald de Piperno said...

Hello Scott,

Thanks for dropping by, and thanks for your comments.

Although I greatly respected Schaeffer when I was a Protestant, and I certainly don't disrespect him now, I stand by my opinion that his attempt to link Aquinas with Descartes fails. I do not see how a man who explicitly declared reason to be limited, and to be dependent upon faith in order to have access to certain truths that are essential for properly understanding man and his place in the world, can be said to have inspired or influenced the views of a man who rejects that dependency, and who explicitly rejected empiricism, Aristotle and scholasticism. Rationalism doesn't depend upon Aquinas.

But if the post doesn't convince you, I'm content to leave it at that.

With regard to your question: for a very brief synopsis of St Thomas' views on man, you might look here. For more details, you could check out his commentary on Aristotle's De Anima (On the Soul), which commentary is available from Amazon and online here (among other places). Of course, if you read that then you probably ought to familiarize yourself with the De Anima, too. You might also check questions 75-102 of the first part of the Summa Theologica, although there might be relevant material elsewhere in ST as well (it's very dense). You'd probably be well-served to ask someone like Ed Feser for more information, since he's an actual professor of philosophy and Thomist, and I'm just sitting around the house typing. :-) I hope that helps.


Scott said...


Thanks for the links you gave; I think they will be helpful.

I would probably agree with you that rationalism does not depend on Aquinas. You do a good job of showing in your post the significant differences between the epistemological approaches of Aquinas and Descarte. However, I'm not sure that Schaeffer would disagree with you here either.

Schaeffer does not (as far as I can remember) assert that the shift in philosophy was justifiable considering the full scope of Aquinas's beliefs, but merely that Aquinas contiributed to the shift. In fact, I would imagine that Schaeffer would say that rationalism was not an inevitable result of Aquinas's thought, and in fact was not justifiable considering the limits Aquinas placed on reason.

However, this does not preclude the possibility that Aquinas did in fact contribute to the shift. Schaeffer did not argue that the thought of Aquinas and Descarte was identical or even largely overlapping--wat he did argue was that Aquinas's emphasis on reason provided a transition. As he states, "In Aquinas' view the will of man was fallen, but the intellect was not. From this incomplete view of the Biblical Fall flowed subsequent difficulties. Out of this as time passed, man's intellect was seen as autonomous."

Now, I would agree that Schaeffer may have posited this with a bit too much confidence, and probably should have said that the connection was plausible rather than certain. Nevertheless, must it not be admitted that, as far as epistemology goes, Aquinas was closer to Descarte than his recent forbears, and therefore may have provided a sort of transition?

daniel4wr said...


It is very un-Thomistic of you to throw in the towel on a discussion with your “sorry I haven’t persuaded you” tag and then clam up. Now its true, as Aquinas said, that if someone is unwilling to concede any of your presuppositions, there is no point in continuing a debate. But here, we are working off your (and Aquinas’) own presuppositions and showing how they inevitably lead to Descartes’ rationalism which in turn inevitably leads to today’s postmodernism. By giving up as you do it leaves the impression that you are unable to defend Aquinas’ position.

Dan the Interlocutor

Reginald de Piperno said...

By giving up as you do it leaves the impression that you are unable to defend Aquinas’ position.

Your interpretation is unwarranted.

It would be closer to the truth to say that I am attempting to exercise the wisdom taught by this cartoon. :-)



daniel4wr said...


Nice. But I'm right!


Reginald de Piperno said...

But I'm right!

Hence the value in the cartoon. :-)


daniel4wr said...




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Reginald de Piperno said...

Agellius - thanks for the tip. I wouldn't be surprised if you're right.