Opinion #1 (Sri Rama Ramanuja Achari)
From The Hindu Sacrament Of Marriage (srimatham.com):
According to Hindu Law only women have conjugal rights known as the
Ritu. The Ritu which means “season” are the 12 nights after the
commencement of the menstrual cycle, excluding the first 3 or 4.
It is laid down in many sacred texts that it is the duty of the
husband to have sex with his wife during this period. This is known as
Ritu-gamana. After the menstrual blood has ceased to flow, the woman is advised to purify herself by bathing and wearing clean
clothes she should approach her husband and say:— ṛtum dehi — give me
my conjugal rights — the husband has no right to refuse such a
request. (Mbh 13:162.41).
In fact a refusal to oblige is considered a heinous sin leading to
hell! (Parasara 4:12).
In fact it is taught that having sex in the Ritu is one of the virtues that lead to heaven.
The Sacred Law goes even further and declares that the married couple
who only have sex during the Ritu are to be considered as celibate.
This is an interesting law for those who insist on sex only for procreation.
Immediately after menstruation it is almost impossible to fall
pregnant, the all knowing sages and law-givers must have known this
before they formulated such a law and this would support the argument
that the Dharma Shastra does sanction having sex for pleasure alone.
From the above, I infer that using contraceptives like condoms and birth control pills are also sanctioned. Even vasectomy is allowed, not a sin. Remember that previously none of the birth control techniques were available hence the above laws existed to prevent unexpected pregnancies.
Opinion #2 (Satguru Sivaya Subramuniyaswami)
What Is the Hindu View of Sexuality?
The purpose of sexual union is to express and foster love's beautiful
intimacy and to draw husband and wife together for procreation.
While offering community guidance, Hinduism does not legislate sexual matters. Aum.
Sexual intercourse is a natural reproductive function, a part of the
instinctive nature, and its pleasures draw man and woman together that
a child may be conceived. It also serves through its intimacy to
express and nurture love. It is love which endows sexual intercourse
with its higher qualities, transforming it from an animal function to
a human fulfillment. Intensely personal matters of sex as they affect
the family or individual are not legislated, but left to the judgment
of those involved, subject to community laws and customs.
Hinduism neither condones nor condemns birth control, sterilization,
masturbation, homosexuality, petting, polygamy or pornography. It does
not exclude or draw harsh conclusions against any part of human
nature, though scripture prohibits adultery and forbids abortion
except to save a mother's life. Advice in such matters should be
sought from parents, elders and spiritual leaders. The only rigid rule
is wisdom, guided by tradition and virtue. The Vedas beseech, "May all
the divine powers together with the waters join our two hearts in one!
May the Messenger, the Creator and holy Obedience unite us." Aum Namah
Opinion #3 (Swami Chandrasekharendra Saraswati)
From the book, Hindu Dharma: The Universal Way of Life or kamakoti.org:
The householder's life is not to be taken to mean merely the enjoyment
of sensual pleasure along with the carrying out of duties that mean
good to the world. The fact is that the sastras have formulated this
stage of life in such a way as to make kama itself instinct with
dharma. "Dharma" means essentially bringing everything within certain
limits, under a certain discipline and decorum. Kama must be inspired
by dharma, that is one must bridle one's passions in one's conjugal
life, so that, step by step, the carnal urge will lose its keenness
and eventually one will gain mellowness to graduate to sannyasa. That
stage, though, comes later. But at first, even now, in the
householder's stage of life, the passions have to be curbed, little by
little, but not forcibly. In the gurukula the celibate-student is
brought under strict discipline. That saves him from being swept away
by animal passion.
Though we talk of animal passion, we must note that animals mate only
during a particular season. They have the sexual urge only when the
female of the species is ready for pregnancy. Man is baser in such
matters. Brahmacarya helps to control the carnal urge as it first
shows up. Then, in the householder's life, since kama is made
subservient to dharma, the passions are kept under check.
What is the sastric method to control the carnal urge?
From the day of
a women's period there should be no intercourse for four days. Then it
is permitted for twelve days. Again there should be no intercourse
until the women has her next period. Even during the twelve days
mentioned above the couple should not meet during the new moon, on
days conjoined by certain asterisms, etc., If such rules are followed
the couple will remain healthy mentally as well as physically.
I take it from above, all contraceptive methods including vasectomy are allowed, as long as you follow the above rules. Just remember that ultimately you have to give up your sex life and graduate to sannyasa.
Opinion #4 (Swami Satchidananda)
From hinduismtoday.com, although it's a comment on abortion:
Q: How do you perceive the abortion issue and what practical advice do
you give to those seeking your help on this mater?
A: This often comes up. Under most circumstances the abortion should
not be done. Only when the mother's life is in danger - not for any
other reason. Not for any social reason such as, "How can we take care
of this boy?" All those reasons are not good. But there is an old
Tamil saying: "Even the cow, if it comes to kill you, must be killed."
But that is the only time. Some say, "Oh, after six months the life is
there, after six weeks the life is there." No, even the sperm has
life. So, at no point is it not living matter. You are not destroying
the soul but you are destroying the body of the soul. So we don't want
to do that.
I infer from above that, you are not allowed to waste or kill your sperm by any means. Sperm has life. Period.
In one of the comments above, you said:
Well again I would say dharma shastras are far more superior than our thinking. They are commandments of Supreme Bramhan Shriman Narayana. So if they say 'it is a sin' no matter what me, tezz, destroyer, or any xyz person thinks, there would be a sin related to this act.
– Yogi Jul 21 at 12:31
Who is they? "They" means a lot of smritis as I explained in this answer. How do you know which one was authorized by Shriman Narayana in which part of the country or world?
Ultimately, it comes down to 1) where you physically live (local laws) 2) whom you consider your guru and 3) who's opinion you value the most. I think we should just blindly follow one rulebook (e.g., one you've inherited from your parents) and stop constantly questioning whether your guru or parents are teaching you the most accurate and most shastric way of living.
No offense to anyone nor to undermine our shastras, but there's an old Telugu saying that a couple who followed every rule in the shastras finally gave birth to a dog!
In another comment you said:
Vaishnavism or Sri Vaishnavism and Pancharatra Agamas say it is sin to do the act for purpose of enjoyment. Well technically the egg should be released before the expiration so just the act does not result in child birth. Pancharatra Agamas say that careful analysis of astrology and time constraints should be done before doing the act. it makes clear statement that the act if done without such speculation and aim then it is a sin resulting in anartha. – Yogi Jul 21 at 13:53
Ok, well, if you are follower of Pancharatra Agamas, then, those rules only apply to you. Not for everyone. If you already know the answer to your question, maybe you should post one instead of waiting for one that 'fits' with your thinking.