We discussed (The Science of) Friendship. The Guardian Reviews and YouTubes with and by Ben Rein tell us that lack of human interaction is bad for our health: we evolved as a highly co-operative species, so it is perhaps unsurprising that we are punished for isolation.  In the absence of other humans, interacting with dogs works, and we note that dogs have evolved this compliance from wolves that don’t have it.  AI 'companions' are improving and will no doubt get really convincing, and that will be OK as long as we don’t forget that they are, as dogs are, a substitute for the real thing.  Friendship is much more than just interaction, so what makes friendship?  We looked at various ideas from antiquity (Aristotle and Cicero) and Stanford Encyclopaedia.  A friend is more than someone who can give us advantages or preferment or entertain us: We agreed we befriend those who share most of our core values, and whom we like and want to support as much as depend on.  Differences of opinion, beliefs and lifestyles can, and should, be accommodated, as they benefit both parties.  We then recognised we get our core values from previous relationships and friendships and from the society we live in.  Society’s norms do change over time, so varied friendships help us keep up with the times and other cultures.