E. coli bacteria has the ability to sense chemical gradients and to move in the direction of food. It uses its flagella (long filaments) to either run or tumble. Running takes it in a straight direction, whereas tumbling allows it to change directions. The bacterium is so small that its sensors can't tell the direction from which a good or bad chemical is coming from. But it uses time to compensate for its lack of spatial awareness. It doesn't care how much of a chemical is present, but whether it is increasing or decreasing over time. If a good chemical is increasing, it will continue swimming in that direction. If it's decreasing, it will swim in a different direction. Since we evolved from bacteria, it is very likely that we have inherited this internal sense of whether we are moving towards something better or worse. This is the "inner teacher" of Parker Palmer. It is also how the Feldenkrais movement philosophy works. In the end, we can only trust our innate sense of the good.