Meditation on Emptiness, 633; Jam-yang-shay-ba's Great Exposition of Tenets, 72; Annotations, page 134.
The meaning of the passage from [Chandrakirti's] Clear Words, ["The MÓdhyamika's are undistinguishable from Nihilists because they propound that virtuous and non-virtuous agents, actions, fruits, and all words are empty of inherent existence" 134ja3] is as zong-ka-ba's Great Exposition of Special Insight says:
Although both acting with equanimity when one has not analyzed and acting with equanimity having has analyzed are similar in being [instances of] acting with equanimity, they are very different, because the former is entangled in ignorance while the latter is used by Buddha 134ja1 
Similarly, the Nihilist 134ja2 view that former and later births do not inherently exist is posited through the force of their being obscured by ignorance, but the view of the Proponents of the Middle that former and later births do not inherently exist is preceded by analysis by a reasoning consciousness. Even though the mere words--"a view of no inherent existence"--are similar in the two, there is a very great difference in meaning.
It is as follows: a Nihilist asserts actions and their effects and future lives to be non-existent, but Proponents of the Middle assert these to be without inherent existence. Hence, there is a difference in their thesis.
Proponents of the Middle assert actions and effects and so forth lack inherent existence because of being dependent-arisings. Nihilists do not take [being a dependent-arising] as a reason [that things lack inherent existence] because they do not assert that actions and effects are dependent-arisings.
There is a great difference in reasons [used by the Middle Way School and the Nihilists] because the Nihilists assert [past and future lives] to be non-existent using the reason that they do not see present sentient beings coming here from a previous life and going from here to a later life.