Rajendra Bhatia's Notes on Functional Analysis (Texts and Readings in Mathematics), Pg. $14$ states (without proof) that:
Every $\ell^p$ space ($1\le p \le \infty)$ with $p\ne 2$ has a subspace without a Schauder basis.
where $\ell^p$ denotes the sequence space with the $p$-norm.
What is the proof of this fact? I have been trying for a while now, and it seems more difficult than I had imagined.
Also, I would be interested to see why every subspace of $\ell^2$ has a Schauder basis.
P.S. If the proof is doable with some hints, then just hints would be great too!
Update: The proof of the main assertion is found in Lindenstrauss and Tzafriri's Classical Banach Spaces I and II, as mentioned by David Mitra in the comments.