The Divine Lamp

Article I

The System of Locke
It must be confessed that the celebrated Locke perceived the difficulty of which we are speaking more imperfectly that any other philosopher, or at all events he did not seriously consider it. We shall nevertheless find that he also fell in with it in the coarse of his investigations. (concerning the difficulty Locke failed to perceive, see the PREVIOUS INSTALLMENT)
This philosopher with the greatest bonhomie imaginable assures you at the outset that all our ideas are derived from sensation and reflection, in the same way, one might think, that the waters of the reservoir are supplied from two large fountains.

Article II

Locke, when coming to account for the origin of the idea of substance, stumbles upon the difficulty, but does not perceive it.

Having thus taken the principle of his system for granted at the very commencement, Locke proceeds to apply it, passing in review the various species of ideas, and showing how their formation can easily be explained by sensation and reflection alone.

To test the principle of a system by its application is, undoubtedly, a thing much to be commended; for it is the only proper way of ascertaining if the principle be sound, or, if not, of discovering where its weak points lie.

In fact, it was during this process of application that Locke stumbled upon the difficulty. Among the various species of ideas which came in his way there was also the idea of substance; and by no amount of ingenuity could he, on the ’sensation and reflection’ principle alone, account for the production of this idea.

Placed in this dilemma, what did he do? Rather than admit that his fundamental principle was defective, because insufficient to account for the formation of all our ideas, he boldly took it upon himslef to assert that the idea of substance was a mere dream!

‘I confess’, he says, ‘there is another idea which would be of general use for mankind to have, as it is of general talk, as if the had it; and that is the Idea of Substance, which we neither have nor can have by sensation or reflection.’

The reasoning of Locke, put in the form of a dialogue, would come to the following:-

Locke: The origin of ideas, like everything else, must be discussed on the basis of facts.

Opponent: Nothing could be better; but pray what are the facts you would start from?

Locke: Sensation and reflection.

Opponent: Well, but how do you, from these two faculties, derive the idea of substance?

Locke: It cannot be derived from them; therefore it does not exist.

Opponent: Pardon me, but I am unable to see the force of your deduction. Sensation and reflection are certainly two facts; but it is also a fact that we have the idea of substance. Now, by what right do you exclude this third fact, simply because it happens to be out of harmony with the two which you have selected as the basis of your philosophy? Questions of fact are not to be settled by reasoning, but by observation. You, on the contrary, start from reasoning in order to deny fact. You say the idea of substance does not exist because it cannot exist, and it cannot exist because it is not derived from sensation and reflection. Is this not going counter to the method which you have, and very properly, laid down for us all? According to this method, you ought to have examined, first, if the idea of substance exists; and if you found that it does exist, you ought to have said, ‘therefore it can exist.’ Any one fact is as much a fact, and therefore as much entitled to recognition, as any other fact. This rule of justice you have clearly violated. From a desire to hold fast by your favorite theory, you have unduly extolled some facts at the expense of others, and I must therefore, on these grounds, be permitted to call your argument a blunder.

I do not see how this reply could be validly gainsaid by a follower of the school of Locke. (excerpted from THE ORIGIN OF IDEAS, Vol 1, by Blessed Antonio Rosmini. Public domain book)