Babies need to learn to self-soothe, and letting them cry themselves to sleep is the simplest way to do this. Essentially sleep training, the Ferber Method is perhaps the most well-known and controversial program that urges parents to limit physical contact with a crying child at bedtime and throughout the night. If followed properly, it does not promote abuse or negligence in any way. It teaches a child that crying will get nothing more than a brief check-in from Mom and Dad, and it also allows everyone in the home a better night's rest.
A mother should be aware of when her baby is crying and if he/she/it needs attention(diaper changing, a bottle, a nap, or another necessity) then it should be given to the baby. However, sometimes, babies cry for no reason, other than to cry. If a mother tends to the baby every time it cries, it will think every time that it cries Mommy will come running to help. This can lead to other attention issues as the infant gets older and matures.
Babies cry, babies cry for no reason sometimes. If you attend to a baby every single time they cry they will cry for no reason other than "where is mommy?" and that will get annoying and frustrating for the parent and anyone who ever babysits the child. As long as the baby isn't needing a change of diapers, food, sleep, or anything else that is a necessity, let the kid cry it out. Coddling and doting the baby won't do anything but make it cry nonstop, good luck finding a babysitter that sticks with you with that sobbing baby! YIKES!
Allowing a baby to "cry it out" is one thing but one should consider the length of time allowed for the behavior. There are other methods one could use rather than simply allowing the baby to "cry it out". One should attend to the child and try to understand the reason for the frustration and work on the situation. I can't see how allowing a child to "cry it out" could be beneficial to the child nor the adult.
On your first child the idea of innate knowledge is in error.
No one does, i had no innate knowledge and had to establish exactly what was the problem. Often as it turned out, it was winding, because my son was impossible to wind. And multiple methods did not work.
Eventually we found methods that did in combination with each other. This reduced some crying, also, he was awake much more and reversed, ie his day time was sleeping, night time constantly awake.
Also he would cry when hungry, when soiled, when he wanted a cuddle.
Crying is a signal for something, and my cuddling and attending did not make a constant crier.
If i had not attended, i would merely have a child that learned no one comes and that it would stop crying when exhausted, i felt enforcing a routine by my choice was pointless, if we say as adults that negative emotions are bad, why would it be different as a baby?
So upon a cry i would go check, and in no time it took me moments to establish the cause. And it took a couple of months to get his sleep pattern changed bit by bit, and then there were nights still when he would cry, but i developed a method that got him to sleep.
The oft suggested method merely means i could have left a soiled child in distress or hungry or sad. Etc
My son never suffered nappy rash, was mainly happy, never screamed and screamed until fed at the convenient parent appointed time.
I moved into routines, and eased into a system of checking what was needed, he was a happy baby, and and little screaming and crying, he never screamed and screamed for attention because he did not have to, when he was asleep he didn't need it, when he woke and cried the routine meant it wasn't all hugs and kisses, and it took very little when that was what was wanted, to soothe and why should i have cared, did i have a child so i could dump it in a cot and relax?
There is always a reason for the crying, always, despite the assertion by others. My child is soon to be seven, is not clingy but is happy to be hugged, is a lovely child and tops their class in many areas, is kind and caring, undemanding and so i can say what i did has not only been good asa baby for me and himself, it was no detriment as he has grown. But i am not a mother, i am just a father.