Obviously, one of the things I found interesting was the philosopher Edmund Montgomery (1835-1911), about whom I don't think I had heard before. It turns out he was well respected and rather prolific, with a large number of articles in Mind, The Monist, and the International Journal of Ethics. There was a brief resurgence of interest in him in the 1950s, but other than that he seems to have faded completely from view (as many respected philosophers at that time have). He continued his scientific work to the end (at one point studying protoplasm and one-celled organisms every day for five years straight). He was a sort of vitalist, and so one of the running themes in his scientific work is that it is impossible for life to be nothing but an interaction of cells. One of his usual points, found, for instance, in "Are we 'Cell Aggregates'?" (Mind 7.25 (1882): 100–107), is that by definition a cell is a relatively autonomous unit, so the claim amounts to saying that all activities of living organism consist of nutrition and very limited cell-to-cell stimulations, which leaves mysterious how any of it gets coordinated at all. One of the things he was particularly interested in, on this point, was the capacity of complex organisms to rebuild and reconstitute themselves. His conclusion was that organisms are in fact relatively fundamental unities; composed of many molecules, they nonetheless in some ways function as if they were single molecules. His position seems to me to be sometimes misrepresented -- his claim is not that there weren't biological units we could call cells, but that it is not possible to understand cells fully except as parts of living organisms -- even with unicellular organisms, it is their integrative activity as organisms, not their relative autonomy as cells, that is the primary principle of explanation. His own view was that biological phenomena strongly indicated that life consisted in an "identical, indivisible, perdurable, and self-sustaining substance" (“The Substantiality of Life”. Mind 6.23 (1881): 321–349), a sort of monad integrating the various phenomena we associate with living things. He often calls this the vital organization, thus leading to the name occasionally given to his philosophy -- the Philosophy of Organization.
Another of his ideas, closely related to this, was that psychology was the purest science, because it was the only one in which the phenomena are directly observed -- all other sciences are built entirely on psychological phenomena and our assumptions about them. (See on this point, for instance, “The Unity of the Organic Individual”. Mind 5.20 (1880): 465–489, particularly 488-489.) He was also firmly opposed throughout his philosophical career to the notion that we could have any kind of a priori knowledge, so he thought that psychology could only serve in this role if it recognized that consciousness was interacting with a real world:
I am confident that positive proof of the existence of a world of efficient powers beyond our conscious content -- a world to which our own efficient Subject belongs -- can be readily given to all who admit the existence of other beings like themselves. For it is incontestable, and in keeping with the forceless character of psychical occurrences, that we become conscious of the existence of other beings, not in the least through awareness of anything forming part of their conscious content. When we perceive another human being, this perception does not contain any of his conscious states.[“Mental Activity”. Mind 14.56 (1889): 501-502; emphasis in original]
In a sense, he can be seen as trying to find a middle way between idealism on the one side and mechanical materialism on the other; this aspect of his view he often calls Naturalism.
Despite his prolific publication, Montgomery was relatively isolated from the main streams of intellectual activity, and has occasionally been given the epithet 'the Hermit Philosopher of Liendo', Liendo being the name of his plantation in Hempstead, Texas.