  We characterize $t$-structures in stable $\infty$-categories as suitable
quasicategorical factorization systems. More precisely we show that a
$t$-structure $\mathfrak{t}$ on a stable $\infty$-category $\mathbf{C}$ is
equivalent to a normal torsion theory $\mathbb{F}$ on $\mathbf{C}$, i.e. to a
factorization system $\mathbb{F}=(\mathcal{E},\mathcal{M})$ where both classes
satisfy the 3-for-2 cancellation property, and a certain compatibility with
pullbacks/pushouts.
