STM, agents/actors, et al. are not "mutable global variables" -- they are all ways of working with state within the bounds of defined semantics. Huge differenc

STM, agents/actors, et al. are not "mutable global variables" -- they are all ways of working with state within the bounds of defined semantics. Huge difference, and largely irrelevant to the current discussion. Who said anything about mutating global state in random ways? All you need is to have some state mutated in some way that you aren't aware of to make life hell in an imperative environment. Considering that that happens all the time, especially given the modern conveniences of large frameworks and libraries... > But, again, a combination of passing things conservatively, > naming functions well, and making heavy use of > const/final/sealed/what have you to lock things down makes > this problem largely absent in practice. This is flatly wrong, and equivalent to saying that you can write concurrent code in an imperative environment without a problem as long as you use locks just right.