1. Good Aristotelian that I am, or at least neo-Aristotelian, I introduce and make use of the principle of non-contradiction, that

No being can both be and not be, in the same respect and at the same time.

in virtually every course I teach. One immediate application of that principle is the thesis that

No being can both be in any one place and not be in that same place, in the same respect and at the same time.

2. I have found that students sometimes have difficulty understanding the difference between that thesis and the thesis that

No being can both be in one place and be in another place, in the same respect and at the same time.

My attempts at getting them to see the difference have seldom gone much beyond (1) repeating the two theses slowly and (2) and then pointing out that the thesis of divine omnipresence of classical theology, that

At least one being, God, can both be in one place and be in another place, in fact, in all other places, in the same respect and at the same time.

is not the same as the thesis, contradicting the principle of non-contradiction, that

At least one being, God, can both be in one place and not be in that same place, in the same respect and at the same time.

One can, that is, consistently uphold both the principle of non-contradiction and the thesis of divine omnipresence.

3. I believe I have found a more helpful, because more concrete, first exemplification of the difference at hand, for another immediate application of the principle of non-contradiction is the thesis that

No person can both be a citizen of any one nation and not be a citizen of that same nation, in the same respect and at the same time.

I have found that students have little difficulty in understanding the difference between that thesis and the thesis that

No person can both be a citizen of any one nation and be a citizen of another nation, in the same respect and at the same time.

or its equivalent

At least one person can both be a citizen of any one nation and be a citizen of another nation, in the same respect and at the same time.

for they can see that, in fact, not just one person, but many persons are citizens of two nations; they hold dual citizenships.

In my efforts to make clear that the principle of non-contradiction does not rule out a being’s being in one place and in another, I will in the future bring in the possibility of dual citizenship before that of divine omnipresence.

Until next time.

Richard