be illegal, or
without sufficient cause, the prisoner is set at liberty.

Sec.5. The next clause declares, "No bill of attainder or _ex post facto_
law shall be passed." A _bill of attainder_ is an act of the legislature
by which the punishment of death is inflicted upon a person for some
crime, without any trial. If it inflicts a milder punishment, it is
usually called a bill of pains and penalties. Such laws are inconsistent
with the principles of republican government, and are therefore properly
prohibited.

Sec.6. An _ex post facto_ law is literally a law made after an act is done,
or which has effect upon an act after it is done. But it here means a
law that makes punishable as a _crime_, an act which was not criminal
when done. A law is also an _ex post facto_ law that increases the
punishment of a crime after it has been committed. If, for example, a
law should be passed by which a person, having previously killed another
in lawfully defending his own life, should be made to suffer death, it
would be an _ex post facto_ law, because killing in self-defense, before
the passage of the law, was not punishable as a crime. Such also would
be a law that should require all persons now charged with stealing, to
be imprisoned for life, if found guilty; because the crime, when
committed, was punishable by a shorter imprisonment.

Sec.7. The next prohibition is, "No capitation or other direct tax shall be
laid, unless in proportion to the census or enumeration herein before
directed to be taken." The words _capitation_ and _capital_ are from the
Latin _caput_, the head, or poll. Hence a _capitation-tax_ or a
_poll-tax_, is a tax upon each head or person. (Chap. VII. Sec.4.) The
above clause means, that poll-taxes, if laid, must be laid in conformity
to article 1st, section 2d, clause 3d, of the constitution, which
requires three-fifths of the slaves to be counted in apportioning taxes
among the states according to population.

Sec.8. The next prohibition is, "No tax or duty shall be laid on articles
exported from any state." Probably no law for taxing exports could be
devised which would operate equally upon the interests of the different
states. Or some states the principal product is cotton, rice, or
tobacco; of others, grain; and of others, manufactures; and some of
these products might not bear the same rates of duties as others. But
though it were possible to devise a plan which would be equal in its
operation, a m