I’m not a proponent of the idea that we are the sole intelligent species in the galaxy, but I think it’s at least plausible. In my mind it boils down to statist

I’m not a proponent of the idea that we are the sole intelligent species in the galaxy, but I think it’s at least plausible. In my mind it boils down to statistics. Basically, it seems to me that many, many conditions have to come together for life to emerge at all on a given planet, and then many, many more conditions have to develop for intelligent life to emerge. If the denominator in that probability is significantly larger than the number of planets in the galaxy, then the probability of any given galaxy harboring intelligent species would be approximately zero. Similarly, the conditional probability that there are at least two intelligent species in a galaxy given there is at least one (namely humans here on Earth) is still approximately zero.