  The spin polarizabilities of the nucleon describe how the spin of the nucleon
responds to an incident polarized photon. The most model-independent way to
measure the nucleon spin polarizabilities is through polarized Compton
scattering. Double-polarized Compton scattering asymmetries on the proton were
measured in the $\Delta(1232)$ region using circularly polarized incident
photons and a transversely polarized proton target at the Mainz Microtron. Fits
to asymmetry data were performed using a dispersion model calculation and a
baryon chiral perturbation theory calculation, and a separation of all four
proton spin polarizabilities in the multipole basis was achieved. The analysis
based on a dispersion model calculation yields $\gamma_{E1E1} = -3.5 \pm 1.2$,
$\gamma_{M1M1}= 3.16 \pm 0.85$, $\gamma_{E1M2} = -0.7 \pm 1.2$, and
$\gamma_{M1E2} = 1.99 \pm 0.29$, in units of $10^{-4}$ fm$^4$.
