How can capricorn be stable and capricious at the same time?

* In the 30+ years I have been studying astrology I have never heard of Capricorn being described as capricious. That's quite a reach to say that, I'd like to know who said that. Capricorn can be emotional, but I see capricious as being more whimsical, more like Uranus rather than Saturn or Cap. They are not that, IMHO