PART ONE

THE CRITERION OF CERTAINTY

CHAPTER 1

The nature of certainty, truth, and persuasion

1044. ‘Certainty is a firm and reasonable persuasion that conforms to the truth.’

1045. Truth in the human being, therefore, is not the same as certainty. I can have a true opinion present to my spirit, yet doubt its truth. In this case I do not have certainty.
It is not sufficient for a thing to be true in itself in order for it to be true for us also. If it is to be true for us, we must have a motive producing a firm persuasion in us, and producing it reasonably, that is, according to a reason which must convince us that our opinion or belief is true and undoubted.(3)
Although logical truth certainly has no existence in itself outside all subsistence, it exists in itself outside the human intellect. This justifies the distinction between something true in itself, and true for me as a result of the certainty I have of this truth. All this is evident, and for the moment I need not investigate the nature of truth any further — I shall do this elsewhere.

1046. The definition I have given of certainty shows the difference between certainty, persuasion and truth.
Persuasion can be very firm (or declared so by the person who has it), but about something false. This is not certainty.
Persuasion can be very firm and even conform to the truth, but rest on a false and unreasonable motive.(4) In such a case we would be persuaded of the truth and partly possess it, but we would not, strictly speaking, be certain unless, of course, we wished to distinguish two kinds of certainty, one reasonable, the other unreasonable. But I am not happy with this distinction which only confuses rather than clarifies the present discussion.

1047. Certainty, therefore, results from three elements: 1. truth in the object, 2. firm persuasion in the subject, 3. a motive, or reason, producing the persuasion.

(3) I call opinion or belief any proposition whatsoever conceived by a human being, to which he can give or deny assent.

(4) Sometimes the motive impelling human beings to a very firm persuasion is reasonable, although they themselves are unaware of its reasonableness and unable to express it. Nevertheless they are certain. We must be careful, therefore, not to confuse belief lacking a reason (or based upon a false reason) with believing as a result of a true reason while being unable to explain the reason. Many people believe the Gospel. When asked, they may not be able to explain why they believe, but this does not mean that they believe without a reason. They believe on divine authority and on the strength of a truth that speaks to them internally. They are convinced by the best of reasons without being able to reflect on it, or note what takes place in them sufficiently well to communicate it clearly to others.