I've always put those huge inverted commas in the air whenever someone mentions pure. It always smells like code for my way not your way.
Ueshiba's aikido changed all the time and not necessarily for the better. Every single one of his students took what they wanted and made it their own (some freely admitting it, others pretending a deeper insight). For me it is impossible to define what pure is and really a futile exercise.
The same goes for Aikido ''philosophy''.