But the minimum is because the Spirit starts with a Force attribute of 2. That sets the minimum. Raising the Force attribute raises the Maximum. The attribute minimums are not set to be the Force attribute.
Except that, again, if that's there intent -- and I'm not saying it is or isn't, trust me -- it's poorly phrased. "This attribute [Force] determines a free spirit's natural minimums and maximums for all attributes." That's what it says. Not "the starting value of this attribute," or "at this very early step in character creation, this attribute," or "When it's at two, this attribute," or anything else.
It just says
this attribute, and then goes on to explain that it sets minimums and maximums. Later in the paragraph it only says maximums -- but it's really up to any individual read (and as such, the balance of any given game table) as to whether or not the word "minimums" is then just thrown out and ignored, as you continue to read.
If it's there intent that attributes start at 2, and need to be bought up later -- and it may very well be, like I said I'm not saying that's wrong -- then it would have been much cleaner, and even taken less words, to say "A free spirit's attributes, including Edge, Magic, and Force, all have a minimum of 2. Throughout play, their attributes have a maximum of their Force score, which has a natural maximum of 6."