If the Samkhyas are the Christians who are the Vaisheshikas and Naiyayikas?  Essentially, they are the materialists or the scientists or the atheist. They are the people who say there is just the material world. Everything can be explained in terms of physical phenomena. Much of modern psychology has attempted to try explain everything that happens within the mind as the product of physical evolution or biological processes occurring inside of the brain.  As we go through the refutations of this school, we should have that sort of thinking in mind. There is part of us that still thinks everything is just material and that the mind is the brain.  

(9.68) The material I asserted by materialists also cannot be the I,
Because it is devoid of mind, just like a jug.
(Vaisheshika and Naiyayika) “But it has a relationship with mind and so it can know objects.”
When the self, or I, comes to know something, the former self that did not know ceases;

(9.69) But if, as you say, the self is permanent and unchanging,
How can it form a relationship with mind and become a knower?
Saying that the self is devoid of mind and unable to function
Is like saying that space is the self or I!

Materialist psychologists do not have an answer for how the physical organ of the brain can know a non-physical object. They simply observe that we do know things and they observe that we have a brain, therefore they conclude that somehow the brain can know mental objects. What’s interesting is the materialists consider those who believe in spiritual matters are naive and that they are the scientists. But in truth they are the ones that make the leap of faith that is somehow a material substance can know.