The Philosopher's Tone is designed to do all the usual pedal compressor tasks, but also has smooth diode clipping distortion on tap to dirty things up.
Sounds
The PT can tighten up dynamics for arpeggiated chords or country picking as well as delivering a shedload of clean sustain, but it has more tricks up its sleeve.
The treble knob can fine tune the top end, to add some jangle, perhaps, while the blend knob dials in any ratio of dry to effected sound allowing subtle parallel compression and, with the grit turned up, dirty and clean sounds simultaneously.