No, it does not have to be async. My impressions from using Squeak regarding this matter:

1. You can send any message to any object. In case the object does not have a suitable handler, you will get an exception: <object> does not understand <message>. The whole thing is very dynamic.

2. There is no `static` BS like in c# or java. This is because each method has to be a method of an object. For each class there is a metaclass which is an object too, see: https://en.m.wikipedia.org/wiki/Metaclass#/media/File%3ASmal...