Believe in order to understand

Believe in order to understand (credo ut intelligam)

Augustine of Hippo 354 · 430Believe to understand: God in the innermost self.

What it claims

Faith comes first and prepares understanding, which is its reward, but without opposing reason: we understand human speech in order to believe, and believe God's word in order to understand.

Why

Some truths are not yet understood; faith purifies the heart so we may one day see them, and reason is there before it.

The same idea through history

Augustine of Hippo410In Letter 120 (around 410) and in Sermon 43 (date uncertain), Augustine reads in the prophet Isaiah: "If you do not believe, you will not understand". From it he draws a rule: first believe what still exceeds reason, in order to understand it afterwards.

Anselme de Cantorbéry1078In the Proslogion (1077-1078), Anselm takes up the formula: he had first titled his book "faith seeking understanding" (preface) and writes in chapter 1: I do not seek to understand in order to believe, but I believe in order to understand.

Thomas Aquinas1260Thomas Aquinas (Summa contra Gentiles, around 1260) extends the idea by another path: faith and reason come from the same God, so they cannot contradict each other.

In short

"Believe in order to understand" is an argument by Augustine of Hippo (Letter 120 to Consentius; Sermon 43, 410) on the question "Should we believe without proof?" (answer: faith and reason agree). Its claim: Faith comes first and prepares understanding, which is its reward, but without opposing reason: we understand human speech in order to believe, and believe God's word in order to understand. According to AskPhilosophy's logic check (Z3 solver), the argument is valid only if one grants a premise the author leaves unstated (P5). AskPhilosophy presents 3 objections, 3 of them with a documented reply, and the original text behind each premise, checked word for word.

Letter 120 to Consentius; Sermon 43

Valid with an implicit premise

Consentius, a reader of Augustine, wants to understand the mystery of the Trinity. Yet he writes that faith is worth more than reasoning, and that one should follow the authority of the saints rather than ask for reasons. Augustine answers, in Letter 120, that believing does not stop us from asking for reasons. In Sermon 43 he sums the idea up in a formula that will run through the whole Middle Ages: "believe in order to understand". For him faith is not the end of thought but its starting point: one first believes what one does not yet see, and the reward of that faith is to see it. He does not say "do not use your reason". We could not believe without a rational soul, and a reason, even a small one, already persuades us that it is wise to believe first.

click a premise to reject it

If you accept every premise, logic forces you to accept the conclusion. So the debate is about the premises.

Checked by a logic solver: the premises cannot all be true while the conclusion is false.
Without the implicit premise: Without P5, the solver finds a case where truths of salvation are still not understood and the prophet speaks, without it following that one must believe first: the conclusion does not follow.

Valid if P5 is added: P1 gives the reward, P2 and P3 give the occasion and the advice, P4 the place of reason. P5 makes the bridge: the prophet's advice applies to these truths and must be followed. Augustine justifies it himself, but by a reasoning that can remain disputed: if it is reasonable to believe first, then a reason already precedes faith. The argument does not prove that the prophet speaks truly; it assumes it, and that is where critics strike.

Analogy. One learns to swim by entering the water, not by reading a book about swimming. Someone who refuses to enter until everything is understood will never understand. But nobody enters the water without reason: one has good reasons to trust the coach. This reasonable trust is what Augustine calls faith.

Objections

Each objection is a conversation: click to see who replies and where the debate stands.

John Locke 1700 · attacks premise 5

To believe first is to risk believing anything. Faith is assent given on the word of one who speaks in God's name. Whether it really is a revelation from God is not a matter of faith: it is for reason to judge, beforehand.

Augustin replies

see the argument

Augustin Augustine (Letter 120, written before Locke)

If it is reasonable for faith to precede reason in order to rise to things not yet understood, then a reason, however small, itself precedes faith, since it persuades us of it.

The debate goes on (our summary) Augustine does not answer Locke, but he already recognises that a reason precedes faith. Locke asks for more: an examination of the evidence for divine origin before believing. The discussion is about how much reason is required at the start.

Where the debate stands (our summary)Our summary: both agree that faith is not blind and that a reason precedes it. They differ on the threshold: for Augustine, a reason that persuades one to trust the prophet is enough to begin; for Locke, assent must stay proportioned to the evidence of divine origin. No agreement on the core.

William K. Clifford 1877 · attacks premise 3

To believe first and understand afterwards is to believe on insufficient evidence. For Clifford, that is always wrong, everywhere, and for everyone.

a defender replies

see the argument

No reply possible: objection raised in 1877, after the author's death (430).

William James defender of the argument · 1896

James answers Clifford that a rule which would absolutely prevent us from acknowledging certain truths, if they were there, would itself be irrational. For options that evidence cannot settle, one may therefore decide without waiting to understand everything. James does not speak of Augustine.

Where the debate stands (our summary)Our summary: Augustine does not ask us to believe with no reason at all, since a reason precedes faith; the discussion is about the level of evidence needed before believing. Clifford sets it very high for everyone, James allows exceptions, Augustine holds that some truths are understood only after faith.

Tertullian 200 · attacks the conclusion

There is nothing more to seek once one has believed. Tertullian refuses the mixing of philosophy (Athens) and faith (Jerusalem): after Christ and the Gospel, no need for curiosity or inquiry. Seeking to understand is already beginning to doubt. Tertullian writes two centuries before Augustine.

Augustin replies

see the argument

Augustin Augustine (Letter 120, to Consentius, not to Tertullian)

One has the right to ask to understand what one believes, not in order to refuse belief, but to see by the light of reason what one already holds with the firmness of faith.

Where the debate stands (our summary)Our summary: two conceptions of faith. For Tertullian, believing dispenses from seeking; for Augustine, believing opens the search. The debate is old and remains open: it concerns the role of philosophy in the believer's life.