The agony of the rat or the slaughter of a calf remains present in thought not through pity but as the zone of exchange between man and animal in which something of one passes into the other. - Deleuze and Guattari, What Is Philosophy?
I'm not sure I am right about this, but I don't believe in first philosophy. And moreover, I'm not sure thinking there is a first philosophy is particularly useful or helpful. I don't have a clear argument about this yet, more just a feeling I have.