We have a large number of other concepts, also denoted by words, which can be put together in various ways to modify one another, generating new concepts. In some cases we may not be able to conceive of the new or modified concept implied by the juxtaposition of the words – we are not able to accept that it could be true, under any circumstances; we have created a logical paradox. In exactly the same way that other words may be put together, we can juxtapose the word “doubt” with any other word or group of words; and similarly, there will be cases in which this juxtaposition leads to a concept that cannot be logically tolerated. IF SOMETHING CANNOT BE LOGICALLY DOUBTED, THEN LOGICALLY IT MUST BE TRUE.
We find that there are three cases in which this happens:
(1) Definitions: Definitions are true, but only because we make them so. This is reassuring, but not helpful.
(2) The existence of the self, “I”. We cannot doubt our own existence; the concept is meaningless. Although we can put together the words “I doubt that I exist”, it seems logical to us that, if I do not exist, then there is nothing there to do the doubting and so I must exist. The closest we can come to this concept is to doubt the validity of our thought processes; that this inability to doubt our own existence could be a defect of our way of thinking, i.e. the “I” is so constructed as to be unable to logically doubt its own existence even though this could be true. However, the thought processes that we have are all we have to work with; we cannot usefully doubt their method of working – that way lies only total madness and chaos.
Thus we have the first truth, recognised by the earlier philosophers: I am. However, even this conclusion must be limited slightly. It is only true at the moment of consciousness, when I am aware that I am aware. Thus we cannot convincingly say “I was”, just as we cannot be sure that “I will be”. “I am” can only be true in the present, but since every moment is the present, this is no deterrent to our current discourse.
(3) The existence of something which is “Not I”. “I” is the thing that is conscious, is aware that it is aware, the thing that loves, hates, thinks, knows and doubts. But this “I” is receiving sensations from outside itself, which it is not aware of generating, indicating that an external universe, or at least something which is not the conscious “I” also exists. Let us apply our concept of doubt to this external universe, let us doubt that it exists. But if it does not exist, where are these sensations coming from? Perhaps something is only creating the illusion that this external universe exists, but if so, it is certainly not the conscious “I” that is doing so. It is not “I”. Thus we find it logically impossible to doubt the existence of something which is outside of and separate from the conscious “I”. This is the second truth: an external universe also exists.
Therefore we may each conclude that “I” exist, but whether as a corporate being or simply a consciousness, we cannot say. We may also conclude that something external which is “Not I” also exists and affects “I”, although the exact nature of this external universe also remains to be ascertained.
This much can be known.