I'm not comfortable stopping and resting on the determinism of Spinoza. I prefer to go at least as far as Kant, who came later, and his categorical imperative, within which he speaks of autonomy:
The faculty of desire in accordance with concepts, insofar as the ground determining it to action lies within itself and not in its object, is called a faculty to do or to refrain from doing as one pleases. Insofar as it is joined with one's consciousness of the ability to bring about its object by one's action it is called choice (Willkür); if it is not joined with this consciousness its act is called a wish. The faculty of desire whose inner determining ground, hence even what pleases it, lies within the subject's reason is called the will (Wille). The will is therefore the faculty of desire considered not so much in relation to action (as choice is) but rather in relation to the ground determining choice in action. The will itself, strictly speaking, has no determining ground; insofar as it can determine choice, it is instead practical reason itself. Insofar as reason can determine the faculty of desire as such, not only choice but also mere wish can be included under the will. That choice which can be determined by pure reason is called free choice. That which can be determined only by inclination (sensible impulse, stimulus) would be animal choice (arbitrium brutum). Human choice, however, is a choice that can indeed be affected but not determined by impulses, and is therefore of itself (apart from an acquired proficiency of reason) not pure but can still be determined to actions by pure will.
- Immanuel Kant, Metaphysics of Morals, 6:213-4
Categorical Imperative - Wikipedia
Kant does not deny the existence of external causation, and so he is not subscribing to an ultimate free will. He views free will as the power of human reason as it acts within the confines of cause and effect. This is most brilliantly displayed by moral choices, especially in the context of Kant's wider philosophy.
Although I don't entirely discount the philosophies of those preceding Kant, I do view Kant as more or less a starting point for most, if not all, contemporary thought on such matters.