Autor: Feser, Edward

Buch: Scholastic Metaphysics

Titel: Scholastic Metaphysics

Stichwort: Szientismus 2a; S.: Unmöglichkeit einer umfassenden Beschreibung d. Wirklichkeit; Problem: Quantität - Qualität (Schrödinger); Demokrit: Dialog zw. Verstand u. Sinne; Selbst-Widerspruch: Eliminativismus;

Kurzinhalt: ... science cannot in principle provide a complete description of reality... If matter ... is essentially devoid of qualitative features and mind is essentially defined by its possession of qualitative features, then the mind cannot be material.

Textausschnitt: 0.2.2 The descriptive limits of science

12c The second main problem facing scientism, I have said, is that science cannot in principle provide a complete description of reality. Indeed, it cannot in principle provide a complete description even of physical reality. The reason, paradoxical as it sounds, has to do precisely with the method that has made the predictive and technological achievements of modern physics possible. Physics insists upon a purely quantitative description of the world, regarding mathematics as the language in which the “Book of Nature” is written (as Galileo famously put it). Hence it is hardly surprising that physics, more than other disciplines, has discovered those aspects of reality susceptible of the prediction and control characteristic of quantifiable phenomena. Those are the only aspects to which the physicist will allow himself to pay any attention in the first place. Everything else necessarily falls through his methodological net. (Fs) (notabene)

13a Now our ordinary experience of nature is of course qualitative through and through. We perceive colors, sounds, flavors, odors, warmth and coolness, pains and itches, thoughts and choices, purposes and meanings. Physics abstracts from these rich concrete details, ignoring whatever cannot be expressed in terms of equations and the like and thereby radically simplifying the natural order. There is nothing wrong with such an abstractive procedure as long as we keep in mind what we are doing and why we are doing it. Indeed, what the physicist does is just an extension of the sort of thing we do every day when solving practical problems. For example, when figuring out how many people of average weight can be carried on an airplane, engineers deal with abstractions. For one thing, they ignore every aspect of actual, concrete human beings except their weight; for another, they ignore even their actual weight, since it could in principle turn out that there is no specific human being who has exactly whatever the average weight turns out to be. This is extremely useful for the specific purposes at hand. But of course it would be ludicrous for those responsible for planning the flight entertainment or meals to rely solely on the considerations the engineers are concerned with. It would be even more ludicrous for them to insist that unless evidence of meal and movie preferences can be gleaned from the engineers’ data, there just is no fact of the matter about what meals and movies actual human beings would prefer. Such evidence is missing precisely because the engineers’ abstractive method guarantees that it will be missing. (Fs)

13b The description of the world physics gives us is no less abstract than the one the engineers make use of. Physics simply does not give us material systems in all their concrete reality, any more than the aircraft engineers’ description gives us human beings in all their concrete reality. It focuses, as I have said, only on those aspects of a system that are susceptible of prediction and control, and thus on those aspects which can be modeled mathematically. Hence it would be no less ludicrous to suggest that if the description physics gives us of the world does not make reference to some feature familiar to us in ordinary experience, then it follows that the feature in question doesn’t exist. The success of the aircraft engineers’ methods doesn’t for a moment show that human beings have no features other than weight. And the success of physics doesn’t for a moment show that the natural world has no features other than those described in a physics textbook. The reason qualitative features don’t show up is not that the method has allowed us to discover that they aren’t there but rather that the method has essentially stipulated that they be left out of the description whether they are there or not. (Fs)

14a The standard story about how the qualitative features fit into the world is some variation on the distinction between primary and secondary qualities. Colors, sounds, and the like as common sense understands them exist, it is said, only in our perceptual awareness of matter rather than in matter itself, as the qualia of conscious experience. What exists in the external material world is only color as redefined by physics (in terms of surface reflectance properties), sound as redefined by physics (in terms of compression waves), and so forth. But this only makes the qualitative features more rather than less problematic. As Thomas Nagel writes:

The modern mind-body problem arose out of the scientific revolution of the seventeenth century, as a direct result of the concept of objective physical reality that drove that revolution. Galileo and Descartes made the crucial conceptual division by proposing that physical science should provide a mathematically precise quantitative description of an external reality extended in space and time, a description limited to spatiotemporal primary qualities such as shape, size, and motion, and to laws governing the relations among them. Subjective appearances, on the other hand — how this physical world appears to human perception — were assigned to the mind, and the secondary qualities like color, sound, and smell were to be analyzed relationally, in terms of the power of physical things, acting on the senses, to produce those appearances in the minds of observers. It was essential to leave out or subtract subjective appearances and the human mind -- as well as human intentions and purposes -- from the physical world in order to permit this powerful but austere spatiotemporal conception of objective physical reality to develop. (2012, pp. 35-36)

15a The problem is that this method entails that the mind itself cannot be treated as part of the material world, given how mind and matter are characterized by the method. If matter, including the matter of the brain, is essentially devoid of qualitative features and mind is essentially defined by its possession of qualitative features, then the mind cannot be material. Dualism of a Cartesian sort, with all of its problems (the interaction problem, the problem of other minds, zombies, epiphenomenalism, etc.) follows — not as a kind of rearguard resistance to the new scientific conception of the world, but precisely as a direct consequence of it. (Fs)

15b Erwin Schrödinger saw things far more clearly than his scientistic admirers do when he wrote:
We are thus facing the following strange situation. While all building stones for the [modern scientific] world-picture are furnished by the senses qua organs of the mind, while the world picture itself is and remains for everyone a construct of his mind and apart from it has no demonstrable existence, the mind itself remains a stranger in this picture, it has no place in it, it can nowhere be found in it. (1956, p. 216)

15c Also more perceptive than contemporary proponents of scientism was another of their heroes, the ancient atomist Democritus, who saw 2400 years ago that excluding qualitative features from the world is fraught with paradox. An imagined dialogue between the atomist’s intellect and his senses written by Democritus and quoted by Schrödinger (1956, p. 211) goes as follows:

Intellect: Colour is by convention, sweet by convention, bitter by convention; in truth there are but atoms and the void. (Fs)

Senses: Wretched mind, from us you are taking the evidence by which you would overthrow us? Your victory is your own fall. (Fs)

15d Democritus’ point, and Schrödinger’s, is that it will not do to take an eliminativist line and deny that the problematic qualitative features really exist at all. For it is only through observation and experiment — and thus through conscious experiences defined by these very qualitative features — that we have evidence for the truth of the scientific theories in the name of which we would be eliminating the qualitative. Such eliminativism is incoherent. (Fs)