This first comment admits of extension. If we endeavour to introduce experiment (as well as experience) into Mental Science, must we not ask a previous question:--Shall this or that experiment be tried? In other words, by what inner law shall we shape our inquiries so as to gain useful facts for our intended induction?--Nay, we may further ask: What inner Being is to settle the questions, criticize them, and judge the final issue? And if we seem to see our way on these topics, we may feel pretty sure that whenever our psychology comes to practical trial, we proceed as being sure of a Self, more or less _self-conscious of Self_, and are quite confident that its self-ness will continue during the whole time of our investigations. Our second comment may be simply summed, but the consideration given to it ought to be minute and careful. Suppose instead of successive perceptions, impressions, or ideas, we substitute a succession of phenomena, and then apply to them Hume's line of thought, we have an acute statement of the modern teachings which relegate the noblest part of our Nature, our reasonings and our beliefs to the territory of the Unknowable. In a word, all knowledge thus seems to be gained by "looking on," none by "looking in." Truth within ourselves especially if it manifests a Truth above ourselves is made to appear hopeless. And so far does the process of Elimination extend, that principles involved even in our "looking on" must not be drawn out of their latency, for fear they should become accepted parts of knowledge. Let any thinker repeat with this substitution the Personal Identity argument in his own mind, and he will soon see what a shadow is cast over an infinitely wider world of thought.[122] The same process of repetition ought in fairness to produce another effect. Are not these philosophic _argutiæ_, these Pyrrhonic subtilties closely akin to the difficulties raised against _all_ first principles; and more particularly all Theistic principles? But does anybody on their account doubt his own Self-ness or Identity? Or does any one refuse to act on the supposition of _other-ness_, and _outer-ness_, or ignore his world of fellow-men and hard objectivities which press upon him from every side? Why then should anybody ignore on their account the great First-Cause?