II.

The Munich professor has clearly shown to his Berlin colleague that by not recognizing our knowledge of Nature as a real, true cognition, he demonstrated not the limits, but the inanity or absolute impossibility of scien tific cognition. And, consequently, he stands at a purely negative point of view. According to N�geli, Du Bois-Reymond teaches as follows:

Cognition of Nature is the reduction of a natural phenomenon to the mechanics of simple, indivisible atoms.

Atoms in this sense do not exist and, consequently, no real cognition exists.

Even if the world could be understood out of the mechanics of the atoms we would still be unable to understand out of these atoms apperception and consciousness.

On this N�geli justly remarks: “Since the speaker does not proceed beyond mere negation, natural science cannot, in its lack of a proper domain, draw its limits either, – and if it is for ever unable to gain an insight even in the material phenomena, it matters little whether it may possibly lay claim to the spiritual domain.” In other words, if our knowledge yields instead of coffee only chicory, then we only have one bad brew and nothing else. There is nothing good left which it would be worth while to investigate, to understand or to place within its proper limits.

After one professor has thus settled the other, the pleasant duty remains for us to show, what, however, must be clear already, that the Munich professor, too, has landed where the other one was caught. Herr N�geli differs from Du Bois-Reymond in that he has so far broken loose that it is difficult to judge whether it was because his strength has failed him or on account of decorum, that he felt himself obliged to keep to the “mysterious land of presentiment,” to the “divine cognition and omniscience” and such like things which “surpass our human faculties.”

“As regards the faculty of the Ego to know of natural things, the decisive and undoubted fact is that, however our faculty of thinking is constituted, only the sensory perception offers us any knowledge of Nature. If we did not see and hear, did not taste, smell or touch anything we could not altogether know that something exists outside us, – nay, that we ourselves are corporeal.”

These are brave words. Let us adhere to them and see whether our professor sticks to them also.

Our sensory perception, says our lecturer, is limited to the present.

“We cannot in a direct way perceive what was in the past and what will be in the future, nor what is too distant in space nor what is too small or too large in dimension.”

Quite so. But what one man did not see yesterday another one will see to-morrow. Where the distances are too great and the dimensions too small, there we call to our assistance the telescope and the miscroscope. “Thus it is possible, theoretically speaking, for the human organism to get bodily impressions of all phe nomena in Nature. But how does it stand in reality? What impressions are powerful enough to be noticeable to us and what are insignificant enough to pass by unnoticed?”

We are not going to follow the lecturer in all his deails, but will readily acknowledge what always has to be acknowledged,

“Our faculty to get direct perception of Nature through the senses is limited in two respects. We probably (!) lack the perception for whole domains of Nature (is it for that of goblins, ghosts and the like? – J.D.) and so far as we possess it, it merely embraces in time and space an insignificant portion of the whole.” (Yes, Nature surpasses the human mind, it is an inexhaustible object, – J.D.) “Of the constitution, properties, history of a fixed star of the last magnitude, of the organic life on its obscure satellites, of the material and spiritual movements in those organisms – of all that we shall never know anything.”

Here, again, our professor goes too far. Our faculty of research is only limited in so far as its object, Nature, is unlimited. We cannot arrive at any end, simply be cause there is no end. But where there is an end, there we may possibly arrive. No professor can tell how much of the fixed stars and their satellites we and our successors may yet find out, how infinitely deep we may yet penetrate into the past, into the future and into the small est particles, since, as N�geli himself says, we have “theoretically” speaking, every possibility for that. We know that no explorer will ever find two mountains with out a valley, no cutter will ever make a knife without a blade and handle, for these are all theoretical impossibilities. But what results practice will still achieve – to determine that in advance, after the spectral analysis and the invention of the telephone, is surely a piece of impertinence.