sensibility – our capacity to be affected by objects. Sensibility yields a manifold of given sense data called intuitions.
synthesis – a cognitive process of combining a manifold of representations by subsuming them under a concept. Synthesis is the precondition for our ability to cognize objects.
synthetic unity of apperception – the role of self-consciousness in making a synthesis of a manifold of representations possible.
threefold synthesis – a basic form of synthesis that makes up the background processing through which we can acquire representations. It consists of three processes that condition one another: apprehending a manifold, distinguishing individual elements of the manifold, and recognizing them according to a concept.
transcendental deduction – a key argument in Kant’s Critique of Pure Reason. Kant argues that the processes that enable self-consciousness also make cognition of empirical objects possible according to general rules.
transcendental idealism – Kant’s claim that the objects of experience are empirically real, yet transcendentally ideal. This means that anything we can experience as an object is structured by a general lawfulness. However, we cannot know anything about the nature of things considered beyond the human standpoint.
transcendental philosophy – Kant’s philosophical stance in the Critique of Pure Reason. Transcendental philosophy aims to uncover the hidden background conditions that make experience possible and structure experience according to general rules.
understanding (Verstand) – Kant’s term for our capacity to use concepts.
Further reading
Allison, H. (2004). Kant’s Transcendental Idealism: An Interpretation and Defense. New Haven: Yale University Press.
Henrich, D. (1994). The Unity of Reason: Essays on Kant’s Philosophy, ed. R. Velkley. Cambridge, MA: Harvard University Press.
Longuenesse, B. (2005). Kant on the Human Standpoint. Cambridge: Cambridge University Press.
2 The Rise of Experimental Psychology
Kant’s critical philosophy is the most important philosophical precursor of phenomenology. Another important piece of the background to phenomenology is the rise of psychology as a scientific discipline in the nineteenth century. Wilhelm Wundt draws on work in psychophysics by Gustav Fechner to rebut traditional arguments that a scientific psychology is impossible because its subject matter cannot be observed and measured with precision. Kant holds this traditional view, and it is therefore part of the philosophical orthodoxy of the nineteenth century. Wundt’s energetic pursuit of scientific psychology, consequently, brings about a rift and establishes psychology as a separate field, rather than a sub-discipline of philosophy. The relevance to phenomenology is twofold. First, in its beginnings, phenomenology thinks of itself as a type of psychology. Husserl calls it “descriptive psychology.” Its self-conception is bound up with a reconfiguration of the field, which is rooted in basic questions about the nature of the mind. The emergence of scientific psychology contributes to these basic questions. Second, Wundt’s scientific psychology is an important foil for Gestalt psychology (Chapter 5) and ecological psychology (Chapter 10). Both of these approaches interact closely with phenomenology’s conception of the mind and argue against the dominant views of perception and cognition of Wundt’s school.
2.1 Wilhelm Wundt and the rise of scientific psychology
Besides his decisive impact on phenomenology, Kant also deeply influenced the development of scientific psychology, albeit in a more indirect way. While the phenomenologists pursued an openly Kantian project at the margins of the mainstream neo-Kantian philosophy of the late nineteenth century, the rise of scientific psychology as an academic discipline separate from philosophy took a more tortuous path. For Kant argued against the very possibility of scientific psychology, both in his Critique of Pure Reason and in his Metaphysical Foundations of Natural Sciences (MFNS). Given Kant’s stature in the German academy of the nineteenth century, his arguments needed to be addressed by anyone who wished to engage in scientific psychology.
Thus Wilhelm Wundt, the founder of the world’s first experimental psychology lab in 1879 at Leipzig and widely known as the “founding father of psychology,” addresses Kant’s arguments in the early pages of his textbook Principles of Physiological Psychology (1874/1902/1904). He begins with a summary of Kant’s arguments from MFNS:
Kant once declared that psychology was incapable of ever raising itself to the rank of an exact natural science. The reasons that he gives for this opinion have often been repeated in later times. In the first place, Kant says, psychology cannot become an exact science because mathematics is inapplicable to the phenomenon of the internal sense; the pure internal perception, in which mental phenomena must be constructed – time – has but one dimension. In the second place, however, it cannot even become an experimental science, because in it the manifold of internal observation cannot be arbitrarily varied – still less, another thinking subject be submitted to one’s experiments, conformably to the end in view; moreover, the very fact of observation means alteration of the observed object. The first of these objections is erroneous; the second is, at the least, one-sided. (1874, p. 6)
Wundt responds to these objections to the possibility of scientific psychology by drawing on nineteenth-century advances in sensory physiology.
For most of the nineteenth century, our current understanding of the division between the sciences and humanities was not yet in place. Hermann Helmholtz, for example, made crucial contributions in geometry, physics, physiology, and philosophy. In the 1840s, Helmholtz was a member of the Berlin Physical Society, whose members signed an oath to explain life and consciousness in terms of only known physical and chemical principles. Consciousness, that is, is made of the same stuff, obeying the same laws, as everything else in the universe. Helmholtz invented the ophthalmoscope (1850), making it possible to study vision in greater detail than ever before. He also was the first to measure the velocity of neural conduction, which he estimated as 25–40 meters per second. Combined with his views that perceptual experience was nothing other than the activity of neurons, this implies that our experience is not of what is happening right now, but of the very recent past. These and many other findings lead Helmholtz to a detailed theory of perception as unconscious inference that is equally physiological and philosophical and that continues to inform twenty-first-century views of perception.
Along with Helmholtz’s work, members of the Berlin Physical Society and their fellow travelers produced innovations in psychophysics, seeking correlations between changes to the material world and changes in the mind that experiences it. Gustav Fechner’s Elemente der Psychophysik (1860; Elements of Psychophysics) describes decades of work by Ernst Weber and Fechner himself, among others, from the middle 1800s. Research in this period by Weber, for example, focused on just noticeable differences (jnd), differences in physical magnitudes (mass, brightness, intensity of sound) that are sufficient for an experimental participant to notice. For example, participants are given a standard object and asked to wield test objects each of which is slightly heavier (or lighter) than the standard object and to report when they get to a heavier (or lighter) one. The jnd is the mass difference (measured by a non-human device) that leads to a difference in human-experienced mass. Studying this in multiple sensory modalities led to what is now known as Weber’s law: the ratio of the change that leads to a jnd to the standard object is a constant. So, if I is the magnitude of the standard object and DI is the size of the jnd,