Bertrand Russell: Problems of Philosophy Chapter 3 The Nature of Matter

Summary: Believing that he has shown that accepting a world with mind-independent objects is more rational, Russell next considers the nature of these objects. He explains how the science of his day has reduced objects to their motions and positions in space. Scientists admit that the objects may have other properties, but do not require them to explain natural phenomena. However, scientific explanations do not explain our sensations: light is what we immediately see, not a form of wave-motion, even if the sense-data is caused by wave-motion. Thus, a blind man could understand the scientific assertion, but not understand the sensation of light. The sensations of color, sounds, and even our experience of space emerging from sense-data, are absent from scientific discourse. The coin that appears to be oval, but we judge to be intrinsically circular, is so in an idealized space. Hence, science/math's idealized "real space" is public, and apparent space is private. But how are these spaces connected? Russell summarizes the prior conclusion that our sensation of sense-data is caused by matter, independently-existing stuff. If this is the case, Russell believes this presupposes a physical space in which these objects and our bodies are contained where one can pass on sense-data to the other. Sensation of sense data occurs when persons are in contact with a given object (say, an apple) via close bodily proximity, and no other impeding objects (closed cupboard doors) are in the way. Variation occurs through the relative positioning of the body and other objects in science's physical space, and this is borne out well in our private experience. While different spaces emerge in sight, touch, and so forth, we learn to group them together since they bear a similar testament. Russell gives this example: if one sees a house that looks nearer to oneself than another, our kinaesthetic experience confirms this by it taking shorter to reach the house that appeared visually closer. These spaces interlace because there is an actual physical space.

But while private spaces testifies of the real space, we cannot know much about the real space. Russell asserts that we can know only what is required to secure correspondence betwen the private and physical spaces; we don't know anything about the physical space as it is in itself. What this boils down to is us only knowing the "properties of the relations" necessary for holding correspondence. We reason towards the real objects from the sense data, not through the sense-data (studying observations versus the observing). So we can know that during an eclipse, the earth, moon and sun are in one straight line, but not know what a real "straight line" is. We lack the immediate acquaintance with the real "straight line" that we have with a line drawn by a ruler in our private space. Our feeling of duration is often disparate with "clock time" depending on our mental states and activities, so that our experience of time is private, although we recognize there is also a physical time. Despite how long I perceived the basketball game as being, I understand that the tipoff occurred before the end game buzzer. This order of before and after that things appear to have seems to correspond to real time order. It is not the case that the real objects have the same time-order as the sense-data constituting the perception of those objects. Really speaking, thunder and lightning occur at the same time, although I hear the thunder later than its occurrence. Russell also notes the delay in observing star light. Turning to everyday objects, Russell gives more examples of us understanding relational differences in the "real world," due to differences in the apparent one. When 2 objects give visual sense-data of different colors, we reason that there must be something different about the real objects, even though we are not immediately aware of the quality in the real object making it have a specific color. We might naturally assume that the real object has a color (some intermediate color between the various shades appearing at different times and to different people) and if lucky we will catch a glimpse of it. But Russell thinks that this naivity is groundless as we consider the influence of light waves, air, our own eyes; we discover that color is the result of the travel of the ray reaching the eye, not originating in the object itself. Given that a natural assumption about objects' color is wrong, we might wonder if there is any philosophical argument (form/method of reasoning) that can show us if matter is real, it must have a certain nature, so that a more prolonged investigation is unnecessary.