Well, I don't know, let's start with the Spanish constitution [PDF]

Section 16

Freedom of ideology, religion and wors-
hip is guaranteed, to individuals and communi- ties with no other restriction on their expres- sion than may be necessary to maintain public order as protected by law.

So, implicitly, "religion" and "worship" are a separate category from "ideology" since protection of ideology doesn't suffice.

No one may be compelled to make sta- tements regarding his or her ideology, religion or beliefs.

Section 27

The public authorities guarantee the
right of parents to ensure that their children receive religious and moral instruction in accordance with their own convictions.

There is no equivalent protection of the right to have your child educated free of pseudoscience.

Section 14

Spaniards are equal before the law and may not in any way be discriminated against on account of birth, race, sex, religion, opinion or any other personal or social condition or circumstance.

Religion is, again, not opinion, nor covered under "other personal or social condition or circumstance".

Now, this is fantastic. Article 16 is developed in its own law, but only as it pertains to freedom of religion and worship (not freedom of ideology). Now check this out:

La Libertad Religiosa y de culto garantizado por la Constitución comprende, con la consiguiente inmunidad de coacción, el derecho de toda persona a:

Profesar las creencias religiosas que libremente elija o no profesar ninguna; cambiar de confesión o abandonar la que tenía; manifestar libremente sus propias creencias religiosas o la ausencia de las mismas, o abstenerse de declarar sobre ellas.

...

Quedan fuera del ámbito de protección de la presente Ley las actividades, finalidades y entidades relacionadas con el estudio y experimentación de los fenómenos psíquicos o parapsicológicos o la difusión de valores humanísticos o espirituales u otros fines análogos ajenos a los religiosos.

The Freedom of Religion and worship guaranteed by the Constitution encompasses, with the consequent immunity from coercion, the right of any person to:

Profess the religious beliefs they freely choose, or not to profess any; to change confession or abandon that once held; to manifest freely their own beliefs or the lack thereof, or to abstain from declaring on them.

So you're free to be or become non-religious, however

Outside the scope of the present law are activities, ends and entities related to the study and experimentation of psychic or parapsichological phenomena or the diffusion of humanistic or spiritual values or other analogous but not religious goal.

If you are not convinced, try it on someone who has not been entirely debauched by economics. — Piero Sraffa