and does so even in the means of expression one employs and the bare walls it

[suprunp]

145.
That is why there is such an aversion to images and similes within science; here the persuasive and convincing, that which makes credible, is precisely what is not wanted; one challenges, rather, the coldest mistrust, and does so even in the means of expression one employs and the bare walls it presents: because mistrust is the touchstone for the gold of certainty.
(Human, All Too Human; The Wanderer and His Shadow; translated by R.J. Hollingdale)

What does 'it' refer to? (Science?)

Thanks.

[5jj]

145.
That is why there is such an aversion to images and similes within science; here the persuasive and convincing, that which makes credible, is precisely what is not wanted; one challenges, rather, the coldest mistrust, and does so even in the means of expression one employs and the bare walls it presents: because mistrust is the touchstone for the gold of certainty.
(Human, All Too Human; The Wanderer and His Shadow; translated by R.J. Hollingdale)

What does 'it' refer to? (Science?)

Thanks.

I am fairly sure it's 'mistrust'.

one challenges, rather, the coldest mistrust, and does so even in the means of expression one employs and the bare walls it presents: because mistrust is ...

However, it could be 'means of expression', taking the plural form 'means' as singular (this is not uncommon).

It's a difficult sentence.