42. It is the same with love and wisdom, with this difference only, that the substances and forms which are love and wisdom are not obvious to the eyes as the organs of the external senses are. Nevertheless, no one can deny that those things of wisdom and love, which are called thoughts, perceptions, and affections, are substances and forms, and not entities flying and flowing out of nothing, or abstracted from real and actual substance and form, which are subjects. For in the brain are substances and forms innumerable, in which every interior sense which pertains to the understanding and will has its seat. The affections, perceptions, and thoughts there are not exhalations from these substances, but are all actually and really subjects emitting nothing from themselves, but merely undergoing changes according to whatever flows against and affects them. This may be seen from what has been said above about the external senses. Of what thus flows against and affects more will be said below.