Are we Jews superstitious, lured by magic spells and incantations, prone to evoking the power of the symbolic word? Nonsense, one would answer. Superstition goes against the very essence of our religion. And yet there are those who might point an accusing finger to the pageantry involved on the night of Rosh Hashana.
The meal begins in a sea of colorful fruits and vegetables that delight the taste buds, but in reality we are eating special foods whose names, taste or texture conjure positive prayers for a good year. The most popular is the 
There is even a difference of opinion as to whether or not Abraham's servant Eliezer acted correctly.
apple dipped in honey, which occasions our wish for a good and sweet New Year; pomegranates, when we pray for a year of merits as numerous as the pomegranates seeds; etc. And there are even some more modern, even humorous, examples, like dates for the unmarried around the table, and a mixture of raisins and celery for a "raise in da selery." All of this leads our great sages to declare "that on Rosh HaShanah, symbols take on a practical reality" - simana milta hee. Certainly this sounds a bit superstitious.
The Talmud (Babylonian Talmud, Kritut 5b) gives three examples which only seem to aggravate the superstitious element:
1. "Rabbi Ami says one who wishes to know whether he will live out the year ought to bring a candle into a house which is completely sealed off from any wind, and light that candle between Rosh HaShanah and Yom Kippur. If the light doesn't go out, we will know that he will live out the year."
2. "And one who wishes to know if the business venture he wishes to get involved in will succeed or not, let him raise a hen. If she grows big and fat, we know that his venture will succeed."
3. "And for one about to go on a journey who wishes to know if he will come back safely, let him enter a darkened house and remain there. If he sees that his shadow has a shadow, we know that he shall return home safely. But if he doesn't see the shadow, it's no proof that he won't return home safely; perhaps his disappointment and fear in not seeing a shadow of the shadow was responsible for a depression which led to his bad luck."
Now if you think, therefore, that Rosh Hashanah is a legitimate time to allow superstitions to run rampant on the basis of the texts I have just cited, please remember that Rosh HaShanah is also the first day of the Ten Days of Repentance, when every Jew must attempt to be a religiously punctilious as possible. And superstition is halakhically forbidden. Maimonides rules, in his "Laws of Idolatry" 12, 4 (taken from Babylonian Talmud, Sanhedrin 65, 66):
"It is forbidden to engage in soothsaying as do the idolaters, as the Bible commands, 'Do not be involved in sooth-saying.' How so? If someone says, since the bread has fallen from my mouth or the walking stick has fallen from my hands, I shall not go to the place I had intended to get to today, because if I did, my business would fall away from me as well.... And similarly (it is forbidden for) someone to make 'signs' (simanim) for himself that if such and such happens to him, then he will do this and that...."
Along these lines, there is even a difference of opinion as to whether or not Abraham's servant Eliezer acted correctly when he established a "sign" for the choosing of a proper wife for Isaac: "The woman who offers me and my camels to drink the water from the well will be a suitable wife for Isaac." Maimonides is actually critical of such a sign, but the Raavad (ad loc) is vehement that Eliezer committed no transgression, and the Kesef Mishneh (ad loc), Rabbi Yosef Karo, who declares that a righteous individual like Eliezer could not possibly have sinned in such a crucial decision like choosing a wife for our second patriarch, explains the difference. The Bible forbids soothsaying, or "signs," when the sign of a fallen piece of bread is not logically connected to the success of a business venture in a certain place; in the case of Eliezer, however, he understood that the most important quality for the wife of Isaac son of Abraham was kind generosity, not only to a human stranger, but even to an animal. Hence, his action was not a superstitious "sign"; it was rather an intelligent test.
With this distinction in mind, we can understand the message of the Rosh Hashanah signs. Our sages are teaching us the "power of positive thinking," the importance of believing in oneself and in one's message in an optimistic way. If one lights a candle in a room hermetically sealed off from any wind, the candle will not go out. And what the sages want is that everyone believes at the onset of the year that he or she will live to see the year's end. If you believe it, chances are you will.
And if one brings up and nurtures a hen with proper care and plentiful food, of course the hen will grow to be big 
Our sages are teaching us the "power of positive thinking."
and fat; and if you tend to your business venture with the same care and sensitivity, chances are that you will succeed in the business venture as well.
The third example quoted in the Talmudic selection we just discussed is strong evidence that my interpretation is accurate. In the example of the shadow it is certainly logical that in a darkened house the individual will see a shadow to his shadow as night is falling. And the Talmud even adds that even if he doesn't, it is no proof of the failure of his business venture. Even if he should fail, then it was the result of his own fear and frustration in not seeing his shadow's shadow, the fear and frustration which came psychologically because he believed he would fail. It is that lack of self-confidence that we call "bad luck".
This is the strength and force behind the "signs" on the evening of Rosh HaShanah. If we but believe in ourselves and our mission, if we feel that G-d is on our side and we shall overcome, then we will overcome; we will gain many more merits - as numerous as pomegranate seeds - and will vanquish our enemies. If you believe that you're a prince, you'll grow up to be a king.