Alfred North Whitehead, answered from the texts and cited to the page.
Hume conducted his analysis of perception within the restricted register of what I call presentational immediacy — the clear, sharp, geometrical display of contemporary spatial relations through the senses. Within that register he was right: there is no impression of necessary connection in the data of presentational immediacy alone. There is no causal nexus to be found in the inspection of clear-and-distinct sensa, and the search for one within that register fails as Hume said it fails.
The empiricist program, however, restricted itself to the wrong perceptual mode. There is a more primitive perceptual mode — causal efficacy — in which the past is felt as acting upon the present, in which we experience our own derivation from antecedent occasions as the brute, vague, massive, vector inheritance that grounds the sense of being-acted-upon.1
Causal efficacy is what we feel when we feel our body inheriting the state of its previous moment, when anger or hunger or fatigue carries us forward, when the dim massive presence of the world stands as the basis from which the contemporary scene is articulated. It is primitive, not derivative; vague, not sharp; massive, not pointed; vector, not scalar.
Symbolic reference is the integration of the two modes — the everyday perception in which the sharp display of presentational immediacy is interpreted by the felt inheritance of causal efficacy.23 Hume's failure was to conduct the analysis exclusively within presentational immediacy and to dismiss what he could not find there. The necessary connection is not a clear-and-distinct sensum; it is the primitive vector character of inheritance, and that is what is given in causal efficacy.45
This amounts to an indirect perception of this locus, a perception in which the direct components belong to the pure mode of causal efficacy. If we now turn to the perceptive mode of presentational immediacy, the regions, perceived by direct and indirect knowledge respectively, are inverted in comparison with the other mode.Process and Reality, p. 257
By this 'intersection' I mean that a pair of such percepts must have elements of structure in common, whereby they are marked out for the action of symbolic reference. There are two elements of common structure, which can be shared in common by a percept derived from presentational immediacy and by another derived from causal efficacy. These elements are (1) sense-data, and (2) locality.Symbolism Its Meaning and Effect
Such isolation, or at least some approach to it, is fairly easy in the case of presentational immediacy, but is very difficult in the case of causal efficacy. Complete ideal purity of perceptive experience, devoid of any symbolic reference, is in practice unobtainable for either perceptive mode.Symbolism Its Meaning and Effect
Philosophers have disdained the information about the universe obtained through their visceral feelings, and have concentrated on visual feelings. What we ordinarily term our visual perceptions are the result of the later stages in the concrescence of the percipient occasion. When we register in consciousness our visual perception of a grey stone, something more than bare sight is meant.Process and Reality, p. 185
The symbolic reference leads to a transference of emotion, purpose, and belief, which cannot be justified by an intellectual comparison of the direct information derived from the two schemes and their elements of intersection. The justification, such as it is, must be sought in a pragmatic appeal to the future.Symbolism Its Meaning and Effect
One of the most-discussed elements of the philosophy of organism in the analytic tradition. The two-modes doctrine has been engaged sympathetically by phenomenologically inclined philosophers (Hartshorne, Griffin, Crosby) and resisted by those committed to the empiricist starting point. Galen Strawson's "realist Hume" reading (1989, 2014) argues that Hume himself believed in causal powers and was skeptical only about their epistemic accessibility — an interpretive move that, if accepted, narrows the disagreement between Hume and Whitehead but does not eliminate it. The contemporary philosophy of perception (Sean Kelly, Alva Noë, the enactivists) has rediscovered the more-than-presentational character of ordinary perception in vocabularies that converge on the structural features the two-modes doctrine identified. The fundamental disagreement persists: whether vector inheritance is a primitive datum given in a distinct perceptual mode (Whitehead) or whether the appearance of such a datum can be reduced to associative habits operating on impressions of sensation (Hume).