Let's be clear about this. Spinoza managed to, dare I say, intuit, so much in his day that he could not possibly know from the science available to him. His foresight and genius are indeed remarkable and amazing qualities, but nor he or his philosophy were perfect. It was said of Freud that the biggest problem with his theories were that they were too 'perfect' and he had an answer for everything. We know today that Freud's brilliance and his perseverance in establishing psychoanalysis among the sciences is tainted with some glaring and perhaps even dangerous ideas. And yes, even the great Einstein turned out to be wrong a time or two. Infallibility is for Popes; honest knowledge is the domain of the irreverent and often leaves us feeling a little disappointed.
There exists a common danger that devout Spinozists, like myself, in an attempt to reconcile Spinoza to all circumstances, will retrofit later mathematical or scientific discoveries into his philosophy. This is a typical trait of religions and religious mind-sets that view their gods or leaders as infallible and all-knowing. When this occurs, it becomes more of a fan club that a real honest-to-goodness acceptance and analysis of ideas. I suspect that I, too, have been guilty a time or two of this mistake. If you spend enough time with an idea, it becomes sort of timeless. You forget when it started and from where it began in relation to context. One could forget that unlike the late 20th or early 21st century biology student, Darwin, Wallace, or Mendel did not have the broader scope of genetic knowledge we possess today. That they were correct as often as they were, without knowing the true depth of their observations, is still truly amazing!
It is not a brilliant bit of deduction, equation, or experiment that transforms a great thinker into a hero. Our heroes are beloved because they challenged the enforced and regulated status quo of outdated ideas and false beliefs at some danger to their lives and reputations. Men like Copernicus, Galileo, Kepler, Newton, Descartes, Spinoza, Darwin, Freud, Einstein, etc. were not angels or divinely inspired saints, imbued each with intellectual prowess unlike any mankind has ever known previously. There were, in fact, men of greater capability that our heroes used as a foundation for their own endeavors. The distinguishing factor was a curiosity so strong that it simply overwhelmed any reservations brought about by external conditions. They, too, became caught up in the idea, so much so that they forgot their own time and place, thus transcending the existing paradigm to such an extent as to shift the totality of human knowledge from one level to the next, in spite of the danger dissemination of that idea may have posed. That later generations become infatuated with these concepts and their authors is no real dilemma at all. It testifies to the man's overall devotion to a deeper understanding and the roots of discovery. As far as a love affair goes, one could do a whole lot worse.
Yet, with ideas, as in romantic love, there may lurk a dangerous blindness caused by infatuation turned habituation. The psychological associations i.e. culture, behavior, science, etc. that I form when reading the Ethics, while having the benefit of modern neuroscience and psychology at my disposal, are not going to necessarily be the same as those of a 17th century Dutch lens grinder. I should be careful not to project what I know now onto what he knew then. As Spinoza himself would have warned, "Caute!" I can imagine (there I go again!) sitting at a greasy spoon with Benedict while chatting about 'passions and appetites', where he strongly disagrees with everything I say in reference to and on behalf of his philosophy, if for no other reason than to keep things intellectually honest. At least I hope that's what he'd do.
Like a good piece of literature that catches your deepest interests and emotional sensitivity, an idea that takes hold doesn't easily let go, and those which convey a 'common sense' or innovative theory that suits our understanding, can easily transcend time, space, and the accurate, well-placed critique of others. I have to careful to maintain an objectivity and detachment from what Spinoza's philosophy does for me, as me, from what Spinoza actually said as Spinoza. The question to ask becomes "Is it Spinoza talking here? Or is it Shlomo?" Sometimes we must remind ourselves that heroes can still be heroes and be dead wrong about something very important. We should not instinctively rush to their rescue by changing their meaning or context to suit modern mentalities. That is a job better suited for theologians and fanatical groupies.
Deus sive Natura!
"Authenticity matters little, though our willingness to accept legends depends far more upon their expression of concepts we want to believe than upon their plausibility." (David P. Mikkelson)