“An actor should be observant not only on the stage, but also in real life. They should concentrate with all their being… they should look at an object not as any absent-minded passerby, but with penetration. Otherwise their whole creative method will prove lopsided and bear no relation to life.
There are people who are gifted by nature with powers of observation. Without effort they form a sharp impression of whatever is going on around them, in themselves, and another. Also they know how to call out of these observations whatever is most significant, typical or colourful. When you hear such people talk he was struck by the amount that an unobserved person misses.
Other people are unable to develop this power of observation even sufficiently to preserve their own simplest interests. How much less able, then, are they to do it for the sake of studying life itself.”
– Stanislavski