I've been reading WOMEN PHILOSOPHERS OF THE EARLY MODERN PERIOD (1994) a selection of texts from the 17th and 18th centuries edited (and with commentary by) Margaret Atherton.
The collection is rather hit or miss. The women selected have little in common other than sex, chronology, and a western European abode. But it does help fill out some of the history of ideas.
The collection includes for example a vigorous defense of John Locke's ideas about the human mind, written by Catharine Trotter Cockburn.
Defense against whom? Against Cartesians in general. More specifically, against a fellow named Thomas Burnet, who had written extensively against Locke from a Cartesian point of view.
One thought that strikes me here is that by Descartes' time, the terms "mind" and "soul" had become synonymous philosophically. The mind is the immortal part of me if there is one, and if one wants to speak of it in a religious context one can call it the soul. This is in striking contrast with, for example, the old Platonic view that the mind is only one of the three parts of the soul.
Anyway: Locke made the following two points, which struck various Cartesian nerves: first, that if an omnipotent God wanted to make matter think, He could make matter think! There is no logical contradiction involved in saying "I am entirely made of matter and I think." Locke didn't think it true, he believed in an immaterial mind, but he thought it important to make that point about the possibility of thinking matter. Second, Locke said that it is not only possible, it is likely that there are times in the life of a mind when it doesn't think, when it is entertaining no thoughts at all -- as when its body is enjoying a deep sleep.
Cartesians in general, and Burnet in particular, found both points objectionable,. The essence of matter is contrary to the essence of mind thus (on their view) even a omnipotent Being couldn't make matter conscious. Further, that which is conscious must always be conscious, that is, it must always be thinking, although many of its thoughts, even for long stretches, may of course be forgotten.
Cockburn's pamphlet against Burnet, or at least the portion reproduced in this book, is largely aimed at defending Locke from critiques on these two points. And in its defense she says that just because something is "inconceivable" (such as a thinking lump of matter) doesn't mean it isn't so
"All the demonstration we can have from such difficulties [of conception] is of the weakness and scantiness of our knowledge, which should not make us forward in determining positively on either side, much less to establish the immortality of the soul on so uncertain a foundation."
That passage reminds me somehow of The Princess Bride.