I'm curious to understand the specifics behind cards like Clarion Spirit where it states:
Whenever you cast your second spell each turn, create a 1/1 white Spirit creature token with flying.
Does playing that card count as the first spell? I know playing non-lands from the hand are spells, but what about things like Activated Abilities?
For example, what is the outcome of playing the Clarion Spirit, then upgrading my Paladin Class from Level 1 to Level 2; is that enough to trigger the creation of a Spirit Token?
This seems to indicate that a spell is something that uses the stack:
601.2. To cast a spell is to take it from where it is (usually the hand), put it on the stack, and pay its costs, so that it will eventually resolve and have its effect.
And activated abilities use the stack:
602.2. To activate an ability is to put it onto the stack and pay its costs, so that it will eventually resolve and have its effect
Which is then backed up by:
602.2b The remainder of the process for activating an ability is identical to the process for casting a spell listed in rules 601.2b–i.
But at the same time they're in their own section of the rules.
So what is a spell? Is an activated ability a spell?