  “The other difficulty is that these indivisibles cannot be admitted in the case of forms or qualities that are extended in matter or quantity, because otherwise it would follow that two qualities that are maximal contraries with respect to something real and positive belonging to them would be conjoined at the same time in the same indivisible subject, which involves an absurdity. The inference is clear, for suppose that, in the continuous surface of a wall, one half is maximally white and the other half is maximally black, and those qualities each have their own indivisible boundaries [termini] by which they are contained and limited. It will then be necessary that, from that part in virtue of which they are contiguous, they each have their own boundaries inhering at the same time in the same line connecting [continuanti] the quantitative surface. […] From this it further happens that in the same indivisible boundary of matter there would be, at the same, time two specific substantial forms with respect to something that is indivisible in extension.” [Francisco Suárez, Metaphysical Disputations 40, V, §58 (English translation  by Robert Pasnau)]