Different individual consciousnesses plainly differ in having each its own content, in which Schuppe includes each individual's body as well as the rest of the things which come within the consciousness of each; but they also as plainly agree, e.g.
According to Kant, the ob j ective is valid for all consciousnesses; according to Fichte it is valid for one consciousness.
Now, the point of Schuppe is that, so far as they agree, individual consciousnesses are not merely similar, but the same in essence; and this supposed one and the same essence of consciousness in different individuals is what he calls consciousness in general (Bewusstsein iiberhaupt).
Consequently, Kant's explanation of the unity of a thing is that there is always one thing in itself causing in us many phenomena, which as understood by us are objectively valid for all our consciousnesses.
The natural consequence of this theory is that the individual consciousness alone exists (solipsism): this position is, however, open to the obvious criticism that in some cases individual consciousnesses agree in their content.