The purpose of this strand of the blog is to explore religious doubts.  Experience suggests that people have a number of ways of dealing with religious doubts.  The more high-brow read up on apologetics to look for arguments that will rationally squelch them.  The more squeamish may sweep them under the rug and pretend they are not there.  Others try to drown their doubts in raw emotions at revivals.  Finally, some resort to anti-intellectualism and so regard thought itself as an occasion for sin.

All these very different ways of handling doubts have one thing in common:  none of them look at the doubts themselves very closely.  What would we learn if we looked at the doubts themselves?  This blog will explore the different types of doubts which have been brought to my attention by fellow believers, so that others may learn how to deal with their own doubts.

Doubts are so troublesome because people tend to regard all of them as some kind of moral defect.  We will examine some doubts that qualify as defects, but there are other kinds of doubts.  It is not enough to say that doubts form a class, though.  We must also see them against their proper backdrop—certitude.

We first affirm (with Thomas Aquinas) that the intellect seeks truth.1  When the intellect is assured of its possession of truth, it experiences certitude.2  The mind with certitude assents to something for reasons which do not allow any “solid, reasonable misgivings.”3

How does certitude work?

One example is the distance of my home from work.  I have used the odometer to find the distance.  I have measured the distance more than once.  I have no “solid or reasonable misgivings” about the odometer itself; the readings are consistent.  I am sure that if I used any number of other cars, the distance would be the same.  In short, I enjoy the assured possession of the truth that my home is a certain number of miles from work.

Another example is taken from what used to be called the Laws of Thought.  One of these is the Principle of Contradiction, which Richard F. Clarke, S.J. defines as “nothing can at the same time exist and not exist.”4  I enjoy certitude about this principle because there is no way to corroborate simultaneous existence and non-existence.

To illustrate, suppose I have one cat, and I see it go into the laundry room, which conveniently has no exit.  I can verify that the cat is there by seeing it.  Again, if I have one cat and I see it leave the laundry room, I can go in there and verify that the cat is no longer there.  So far, so good.

But if I am told by someone that the cat is in the laundry room and is not in the laundry room, how can I assure myself that the cat is there and is not there at the same time?  Not only can I not imagine the violation of the Principle of Contradiction, but I also cannot imagine a way to prove its violation without resorting to underhanded, verbal tricks.  Therefore, I have perfect confidence in the Principle of Contradiction.

Now, as Rickaby observes, we do not and probably cannot know all things with certitude, yet certitude is the ideal.  If the intellect seeks truth, then its proper function includes acquiring the greatest number of truths.  This it must do without forgetting that some opinions may necessarily remain undecidable, so that we must also experience states of mind which fall short of certitude.  Without this range of states leading up to certitude, we are liable to err either by demanding that all opinions and knowledge produce certitude (dogmatism) or by rejecting certitude out of hand (skepticism).

Our next step is to discuss just those states of mind which fall short of certitude, which will bring us to doubt.


  1. Aquinas Summa Theologiae I, Q. 16, Art. 1.  Aquinas follows Aristotle in defining intellect as a power of the soul and not its essence (see Q. 79, Art. 1).   Aristotle decribes the intellect (nous) the power by which the soul thinks and understands (De anima, bk. III, ch. 4).
  2. John Rickaby, The First Principles of Knowledge, 4th ed. (London: Longmans, Green & Co., 1901), p. 42.
  3. Ibid.
  4. Richard F. Clarke, Logic, 4th ed. (London: Longmans, Green & Co., 1897), p. 33.