  For every $n$-dimensional smooth projective variety $X$ over ${\bf C}$, the
motive $M(X)$ is expected to admit a Chow-K\"unneth decomposition
$M_0(X)\oplus\cdots \oplus M_{2n}(X)$. Inspired by the slice filtration of
$M(X)$ we propose the definitions of $M_2(X)$ and $M_{2n-2}(X)$.
