Everytime we say goodbye,
I die a little.Cole Porter
Consider two different dimensions along which a rationalist account of the emotions might develop.
According to the first dimension, emotions are themselves expressions of reason; they are, or at least can be, a rational, reasoned response to a state of affairs. I will (vaguely) describe this (vague) rationalist view as the view that emotions are inherently rational.
According to the second dimension of a rationalist account of the emotions, emotions – though they may be in some measure rational, even inherently rational – are somehow inferior to the unfettered operation of reason. Perhaps, on this view, emotions cloud our judgment and lead us to misapprehend the truth and to act in ways that are – in one way or another – contrary to reason. I will (vaguely) describe this (vague) rationalist view as the view that emotions are inferior to reason.
These two rationalist dimensions are, of course, not exhaustive: there are, perhaps, many other ways to articulate a rationalist approach to the emotions. Further, these two dimensions are compatible: one can hold that the emotions are inherently rational, but not perfectly so and that other, more purely rational, responses to a given situation are somehow superior. Finally, these views are independent in that one can hold one view without holding the other.
I won't attempt to pin either of these rationalist views (or their denials) on particular philosophers, other than Spinoza. That can only get me into trouble.